Id say the fundamental issue is that it’s not a trilogy, it’s really just three mostly unrelated movies, there’s basically no arc between them. Each movie does have its own problems though, the force awakens too rigorously follows the original, and is boring because we already saw that. The last jedi is my favorite one, rei has a nice arc (though ruined by the next movie) and just in general it tries to be its own thing, snoke dying was amazing and my favorite moment in the trilogy, but it didn’t pan out on any meaningful way. A lot of this movie is built in subversion, which is good upon first viewing but subsequent viewings aren’t as good. The rise of s skywalker is one of the worst films I’m ever seen. Holy shit they ended it so terribly, nobody has a character arc, the villain comes out of nowhere and doesn’t even make sense, like why would you deploy that many ships? You already basically defeated all the resistance. Palatine thinking rei would join him makes absolutely no sense, she literally has no reason to. And her kissing kylo is dumb, there was no buildup whatsoever, and reviving people with the force was never introduced, so you can’t even get invested in it cause you have no idea how it works. Also, this movie has very large parts where the characters just accidentally fall into the plot in really unbelievable ways, and there’s almost no characterization for any side characters. The ending totally ruins the good stuff the last jedi set up, and it’s all in all just a shit movie even if it wasn’t part of a trilogy. There’s also some dumb incels who think that anything with women or a POC means it’s bad, but that doesn’t mean there aren’t valid reasons to dislike the movies.