I appreciate the final scenes and end points of the characters, but the actual work of getting there isn't really a thing in KH3; their arcs are very abbreviated. There's the pre-KH3 stuff which is fine because it focused on them, but then KH3 (understandably) doesn't have the time to continue that work, and just gives them all a scene to conclude their arc.
I mean, honestly, it's probably better than what I expected, since it wouldn't have surprised me if it had been a complete disaster with just how many characters Nomura had to juggle. I guess not juggling them is better than trying and failing.
Aqua's role didn't sit right with me, and Kairi continues to be a complete mess. Master Xehanort's stuff is absolutely a retcon too; I like it for what it is, but it doesn't match with what he was before, so unless you really lean into the corruption angle, it doesn't land right. I suspect Nomura came up with a better idea for him, after BBS came out, and maybe even after KH3D, and just decided to go with it.