Because "reasons"

The ring was destroyed. But little did we know: it's true purpose was to aid in the construction of a Death Star, which is now almost complete...
- Well, Arda is Melkor's ring. He's going to re-shape it into a death star and blow up Illuvatar.

FWIW, Palpatine also came back in the original storyline past ROTJ before Disney retconned the EU. Though they didn't gloss over the "how" bit (he always intended to survive forever and had a clone factory hidden on some planet and used something similar to the force ghost, only he was able to posses his clones).
In the original story, he threatens Luke and his friends while Luke is alone, so Luke goes, "ok I'll join the dark side", gets some training, then switches back the first time he gets ordered to do something he didn't like.
The basic message was "turning to the dark side was only so final for some Jedi because the order itself considered it something that couldn't he undone, while Luke did it easily". Some of the video games touched on this, too, where the light side and dark side were just tools and it was how you used them that determined good and evil. It was also a big theme in ROTJ itself, though not heavily explored after Vader turns back.
There's hints of this in the sequels, but IMO they didn't handle it that well, especially with Luke and Kylo.
- I feel like when people make fun of this, it isn't so much Palpy coming back that they have a problem with, but the sudden and unexpected nature of it. It's such hack writing, and it only happened that way because audiences didn't like TLJ and the people making ROS decided to backtrack on every single one of TLJ's plot threads out of fear instead of making expanding on them for a satisfying finale.
  
  Yeah, it's less about "returned" and more about "somehow".
  
  Yeah, watching those three makes it seem pretty clear that they where made by different people who didn't like what the previous one had done and had an entirely different vision of where star wars should go. Plus a dose of "we want to bring back old characters for fan service, but those characters need to gtfo of the way of these new stars". And then for the two of the biggest ones, they had them die in the dumbest ways.

Through means never fully explained (unless you buy the comics and video games), the ring getting destroyed was all part of Sauron's master plan. The villain for the first two sequels is Samwise's son Bobbit, who Sam tried to kill when he learned he was dabbling in dark arts. He's redeemed by our hero, an orc that broke rank with Sauron after learning about his plan to, IDK, blow up the whole world or something, but he's killed anyway to make room for our third movie reveal that Sauron was behind it all. Our brave orc hero must meet up with a haggard looking Aragorn, Gimli and Legolas to painstakingly re-enact the events of the Fellowship of the Ring, wander around with Gandalf and learn how to become a wizard, then kill Sauron and take the last name Baggins.
- This is painfully accurate and I hate it.
  
  Aragorn: "Somehow, Sauron has returned"
  Elrond: "We'll need a good plan to defeat him."
  Legolas: "And a new fellowship"
  Gimli appearing from off camera: "and...my axe" looks directly at the camera while holding for applause

2 Lord 2 Rings
- Two rings to rule them all!
- Blursed comment

❝But they were all of them deceived, for another ring was made. In the land of Mordor, in the fires of Mount Doom, the Dark Lord Sauron forged, in secret, a Ultra Master Ring™️ to control all others. And into this Ring he poured all his spare cruelty, his extra malice and his leftover will to dominate all life. An Extra Ring to rule them all.❞
- "Now look at this hologram showing the original The One Ring. And now here's The Ultra Master Ring. You can see it's almost three times bigger than The One Ring."
  
  I know this is all in jest, but I imagined a One Ring the size of a hobbit bracelet and then imagined a cave troll discovering it and what sort of dark Lord a big dumb bastard like him would become.
  This is ripe for fanfiction.
- Extra lord of the extra rings, the return of the extra king
  
  How long til LOTR enters the public domain?
- And the shape of that ring? A key blade.
  
  🤮

Sauron checks under the couch cushions and BOOM, more profit!

Imagine all the Hobbits solo spin off shows that i you cant pay me to watch.
- I would absolutely pay money for a slice of life hobbit spin off. No grand quest to save the world, just a few hobbit friends getting into trouble around the Shire and stealing veggies from some farmer's garden before getting drunk at the inn. It's exactly the feel good type of show I like.
  
  I would also be interested in the high stakes political drama of trying to win the gardening competition every year.

Long ago I read some incredibly cursed parody along the lines of "if LotR was a Disney animated film". The songs were absolutely horrifying. I can't find it right now, and I think it's best not to subject you to it anyway.
- Please do subject us, if you find it.

Tolkien himself considered revisiting Middle Earth for a new "uprising", but discarded it because it didn't and probably couldn't recapture the magic. Plus it probably felt too much like reality.
- IIRC, he began writing another installment set in the 4th age, but abandoned it, because now that the main evils were dealt with, all that was left to happen was the world of men betraying each other, and it very quickly became a boring, depressing tale that just didn't need to exist.
  
  Introducing the newest Middle Earth installment: "Tom Bombadill Kicks the Shit Out of Everyone"
  
  "The New Shadow". He wrote about 13 pages and discarded the idea for reasons you mention.
  
  So basically he was going to write game of thrones? Although he may have actually finished it…
  
  The 4th age is game of thrones.

Disney doesn't make movies. They make cringe fan fiction.

"The Ring was destroyed."
"BUT WHAT IF IT WASN'T?"

If disney does what disney usually does, LOTR will be dead to me.
- They're already doing it with TV shows, animated films etc. Disney would just do more of the same, I'd imagine...
  I can only imagine what Jolkein Rolkein Rolkein Tolkein would make of it all.
- Who cares what any of the movies do? The LotR is originally the written work. The books are the substance.
- https://m.imdb.com/news/ni64660240/
- Now is about the time I need to make my obligatory recommendation that you check out the [free] fan-made audiobooks by voice actor, Phil Dragash:
  https://archive.org/details/lotrdragashtracked
  I have listened to these at least once per year since 2015 (holy smokes, that's a decade!), and they are still the best audiobooks I have ever listened to. They utilize music and sound effects from the movies, and Phil has an uncanny ability to replicate many of the movie star's voices. I cannot recommend it enough!

To be fair, the resistance being flabbergasted and in the dark at the return of their dead arch nemesis is actually quite reasonable. The return itself also harkens back to the prequels when Palpatine mentions Darth Plagueis.
The reason the Disney era movies are so underwhelming is a lack of soul and other writing blunders.
- The movies feel like toddlers making up the story as they play with figurines.
  
  Checklist movies. It becomes more important for the movie to have X element due to marketing reasons rather than plot reasons.
  If the movie has more marketing elements than plot elements, it's a checklist movie.
  
  Episode 9, absolutely.
  The Last Jedi is an anarchist critique of Star Wars that somehow got made into a Star Wars.
  
  That got me a chuckle. It does look like that.
  
  Honestly, I'd rather them have let toddlers make up the story while playing with figurines. I was certainly coming up with better plotlines than what they shat out with the sequels when I was a kid.
- Honestly, the idea that the good guys win and then forget that they have to continue to be vigilant and let the evil they defeated come back is as topical now as it was in 2015

How is the last Rings of Power seasons? Haven't watched it yet
- The production quality? Fantastic and even better than season 1.
  The story? I ended the last episode actually angry. I haven't been angry at a piece of media like this in a long time.
- Orcs fighting in direct sunlight, Grand-Alf talking with some guy called Bombadil, and other Shenanigans.
- It's a nice fan fiction with high production quality.
  Story wise, it's as if trying to write the Silmarillion but only using characters from LOTR... It feels a bit flat.
  
  They couldn't get the rights to the Silmarillion sadly. The only canon resources they're allowed to use are the appendices at the end of LOTR. I think they're doing a fantastic job with such limited material. The last two episodes are awesome.
- S1 was alright for a LotR fanfic - so not that great. I didn't get to S2 yet but I heard it's not exactly going up in quality
  
  Why is it so many fiction works that get expanded would do so much better if they just search out actual fanfic and pay those people for their imagination? Instead they get people who aren't invested in the world who do a halfass job that is "canon", yet so far off the mark.
- I'm not a Tolkien superfan, and for me it was mostly just kind of boring.
  Also, this portrayal of Middle Earth seems to have very limited ontological inertia. Everything not on screen might as well not exist. Even the things that are shown feel static and shallow, like there isn't enough "stuff" to actually fill out the world and support the complex societies within.
- I really like the visuals and music. Otherwise, it's polarising to most people.
  
  Yes, went into the first episode all giddy. That was the high point. Seemed to start dropping down after the prologue about Galadriel. I'd have to say that Bombadil is the low so far for me. Of many lows.
- I feel the best advice is to simply watch it and try not to let online opinions sway you until after you've watched it.
  I was dreading it, because I saw a lot of online voices saying it's genuinely the worst thing that has ever been on television. Surprisingly to me, I mostly enjoyed it, although I found season 2 to be stronger than season 1.
  A few parts I didn't like, a couple of parts I mentally even groaned and thought "...why did they do that?", and some other parts I found great.
  Controversial, but overall I've liked it more than parts 2 and 3 of The Hobbit without a doubt.
  
  A lot of the "why did they do that" is explained by not having access to the Silmarillion. They only have the appendices from LOTR. For such crippling limitation I think they're doing a great job. I'm a lifelong LOTR-Silmarillion superfan, I say fuck the Tolkien estate.
- it was great. ill definitely watch the whole series again but ill probably torrent the thing because the amazon video player sucks ass.
- I’m trying to watch it in bits. I’ll watch for 20 minutes or so, then go do something interesting.
- I couldn’t make myself watch the last episode of season 1. There was a lot of eye-rolling and the story just didn’t really capture me.
  The best scenes I can remember was the conversations between Elrond and the dwarf.

Technically, he had like 15 of them things.
- Yes, but it was a bit like having a radio station and 14 small radios laying around 📻.
  
  So one ring is a transmitter and the others are receivers.
- 20 to be exact, 9 human, 7 dwarven, 3 elven and his own

Lots of jewellery. Got to bring it all back to the old volcano. No fly zone for eagles, again. Damn.
- One bracelet to rule them all. Two earrings to find them. A necklace to bind them. Maybe a fancy gold watch.
  
  honestly the idea of a blinged out bad guy who is only powerful due to their 500 enchanted pieces of jewelry is pretty sick, their one crippling weakness is that every step makes them jingle like a christmas carol
  
  Perhaps a diadem? The ol HP-LOTR crossover?

"This won't work Sauron, I am all the Dunedaín !'
- My name is Frodo… Frodo Skywalker.
  
  use the schwarz, frodo!

"Somehow, Palpatine has returned!" v2: LOTR Boogaloo

Oh no, it's a ring dyad!

Probably would make more financial sense to Disney to just wait until it becomes public domain
- I don't know man, the rate we're going 2044 ain't lookin too good...
  
  They're gonna start again beginning with 1 AT

This is kind of the plot of the Shadow of War game, but that's just a non-cannon (I hope) video game, so it was fun