It's hard to properly conclude/end a saga. This movie did a difficult job well.

Rating: 9/10 (2 January 2020)

Most people who're complaining don't realize how hard it is to end a story. In some ways, if you don't end a story correctly, you don't just destroy the ending, you'll ruin every story that comes before it.
You can screw up the first three trilogy massively and still not have the impact that an ending would have.
I have to say, now that I have seen this and every single Star Wars movie since I was a child -- this movie does the ending justice. It's extremely hard, since the original stories, pick your era, didn't really try to leave things in a way that can be tied up. This story did them well. To me, it magnified the entire chorus of the series, so that I feel that going back the rewatching the origins, the reason everything started, made a lot more sense after this movie.
That is hard. Very hard.
Unlike Avengers-Infinity Wars, which had a lot of preplanning built into the stories; and even in that the storytellers had to struggle with Ending them. This one had to tie up an entire universe of actors, backstory, previous threads and even "religious undertones" with the force, to tie them up properly.
Bravo. Don't listen to the naysayers. Go watch it. This is a great movie. If you knew the original star wars, you'll get a lot more out of it; but even newcomers would find it an awesome experience.