Chosen ones, fate, destiny, &c. When you get down to it, a story with these themes is one where a single person or handful of people is ontologically, cosmically better and more important than everyone else. It's eerily similar to that right-wing meme about how "most people are just NPCs" (though I disliked the trope before that meme ever took off).
Way too much importance being given to bloodlines by the narrative (note, this is different from them being given importance by characters or societies in the story).
All of the good characters are handsome and beautiful, while all of the evil characters are ugly and disfigured (with the possible exception of a femme fatale or two).
Races that are inherently, unchangeably evil down to the last individual regardless of upbringing, society, or material circumstances.
Killing hundreds of grunts but leaving the big bad alive because the heroes are better than this. Pure propagandistic brain rot that I'm sure most creators don't even know why they do it.
Spend the finale rightfully knocking Fire Nation airships out of the sky, killing everyone onboard, only to let Ozai live.
And that’s after Aang went fishing around for anyone that would tell him it was okay to spare Ozai because literally everyone around him including his past lives were like “No man you really gotta kill this guy”