The movie is just bad, for so many reasons I don't even know where to start. I'll avoid spoilers as best I can.
1) Palpatine has become a cartoon level villain. Truly awful in so many ways. Not only did they manage to ruin Star Wars, but the one character they hadn't touched before, they completely destroyed in one fell swoop. I guess it's just what they do.
2) The plot is incohesive, and at times plain silly. It just jumps from one thing to the next with out really laying out the ground work for anything, or letting anything develop. A happened, so we must do B, we did B, so now onto C, with out any breaks or exploration of the events that just transpired. In some ways it's like a bad Michael Bay movie (not that there are any good ones really, but still), or a bad improve play, where someone yells "Palpatine is back, and act". I feel like people are just acting for the sake of acting rather than to make a good movie. The fact that there's little to no attachment to any of these characters makes it that much worse.
3) Leia's scenes are weird. Not like Tarkin level weird, it's still her. But because they had only certain lines that they could use, it felt awkward. Someone would say something, and she's there super imposed next to them, with a reply that vaguely fits for an answer to what they're talking about, with awkward pauses in there, that make for really odd scenes. I suppose I shouldn't hold this against them, they did the best with what they had, but I don't know, just takes you out of the movie, more than it helps.
4) The jokes and one lines kind of fall flat. I know it's subjective. I know some people laughed in the theater, while I just sort of cringed, but 90% of them just weren't good. Hopefully you'll like it, so that this movie is at least more enjoyable for you, than it was for me.
5) Honestly I feel like there's a lot, lot more that this movie fails at. However that would begin to go into spoilers. I suppose I'll leave it off on this note, despite how badly I hated The Last Jedi, at least I will say the cinematography of that movie was solid. I can't take that away from it, and while this movie had some decent visual effects as well, it also had some bad ones. A movie that's a quarter of a billion + dollars should not have visual failings of this level. Sadly I have nothing good to say about this movie, other then it's finally all over. I suppose I kinda liked Rey character a bit more than in the other movies, but that's not a high bar to clear. Long live baby Yoda.