Yeah, giving it some time to sit, this is definitely one of my biggest issues with KH3: that, after DDD, we knew pretty much everything would happen in KH3, and that's pretty much exactly what happened, with very few actual twists along the way. Like, we knew that 13 darknesses and 7 lights would be gathered for a final confrontation with Master Xehanort at the Keyblade Graveyard to summon Kingdom Hearts, and indeed that happened. And along the way, it was pretty likely that Ven and Terra and company would be saved, and that they would find some way of bringing characters like Roxas and Xion and Naminé back, and they were. We knew what all of the broad strokes would be and they happened in turn, is what I'm getting at, with little deviation.
It just felt like going through the moments to finally resolve the stuff that DDD and the other games set up, and that's it. Not much in the way of unexpected twists or to make it even worse even character developments or character arcs or anything really, just checking stuff off a list and moving onto the next thing.
And to be clear, before someone says it, yes, there were twists as in stuff like Xigbar being Luxu. But that's just shoved in the epilogue and is more setting up the next games than something that KH3 did much with itself. There's nothing like KH2 starting off with Roxas and who is that guy and going through all that, or it turning out that Ansem the Wise was his own character and that's who DiZ was in CoM, and all kinds of stuff. Then speaking of character development, really nobody in KH3 has arcs or development (aside from the villains, where it's just kind of out of nowhere at the end) like characters like Roxas or Axel or Riku did in KH2, because it's a bunch of nothing happening for most of the game and then just suddenly checking a bunch of stuff off a list once Sora gets to the Realm of Darkness and saves Aqua, and things just shoot off a rocket from there and there's so much to do all of a sudden that they don't really have time for proper character development or arcs for most of a character.