I look for different things depending on the series. In Star Wars, consistent themes are something I look for. That, and an abundance of lore, given that the series is supposed to be about a huge galaxy, where any number of interesting things could be presented. When the reality is that the last movie of this trilogy and a nine-movie saga is going to rehash a villain who was thought to be dead by the end of ROTJ, in a way that had no setup whatsoever, in combination with fumbling the opportunity to do great things with new characters without sacrificing older ones, then I have a problem.
None of this is satisfying. I'm not asking Star Wars to be a heavy drama, even though it can have those moments. I'm asking for it to be consistent and sensible for what it is, and it seems that even ROTS jumps the shark there. You can point the finger at any number of things: TFA not leaving any place for TLJ to go; TLJ not being creative enough to figure out a better way to go from TFA; ROTS paving over TLJ; new characters being squandered when they had potential to do more.
Whatever the case, this trilogy has been a serious case of something that is fun to eat but terrible to digest. Beautiful on the surface, but an unimaginative spectacle. It's unfortunate that this is how the saga gets closed out. What's worse is that these movies will undoubtedly retroactively affect my enjoyment of the cartoons and other supplemental material. This is the penultimate conclusion of the most recent events in what is considered canon for Star Wars. Knowing this is what everything leads up to sucks.
Also I want to add that I've been vocal about how I've come around to disliking TLJ over time. Initially I loved it and while I still recognize many great things about it, I find it to be a slog of a film with a lot of wasted time, among other things. But even though I now dislike that movie, I would have enjoyed it if this movie carried through with whatever TLJ established or was going for. I would have preferred that consistency instead of whatever the hell ROTS chose to do with itself while ignoring its predecessor.