Also it used to be fast, but got bloated and lost its greatest advantage. They abandoned every design choice that made them popular in the first place.
The UI/UX is a convoluted mess. Whenever I say this elsewhere I get downvoted to oblivion and people tell me you just gotta learn it.
Well, yea, that's the problem. I shouldn't have to "learn" a UI, things should be apparent and obvious.
There's not even a useful intro the first time you launch it. Yea, it shows you what the buttons are for, but never explains the concept behind things. Guess you're supposed to intuit that stuff?
To your point, though, the learning process ideally ought to be seamless and linear; each new thing you can do with the application should be mostly obvious given what you already know about the UI, not force you to learn everything from scratch or do work to learn it (unless you're into that kind of thing). I don't think Discord is the worst offender of this rule, but they could make it better.
I do agree with this, however I also have to say being someone who's been on the canary branch and has the newest version of the new UI once you learn it it's so much better mobile wise doing literally anything it just makes sense and goes with the mobile flow a lot better then the old ui was, plus it has a side bar which is really nice... The beginning new ui with the guildbar at the bottom was atrocious though, so glad they scrapped that model.