There's a ton of stuff to nitpick about KH3.
- Poor pacing where 80% of the story is in the last 20% of the game ( all KH games are like this, but KH3 is worse due to the lack of a middle arc )
- Wasted narrative beats with Org13 even during the Disney segments ( we knew that the New 7 Princesses of Lights weren't gonna have a role in this, but I guess the game needed to justify why Org13 were messing around in new worlds instead of preparing for KBW )
- Even more wasted narrative beats used to set-up sequel ( The scenes where Axel/Ansem/etc were talking about Mystery Girl/Box were not insignificant at all )
- Kairi's fridging
- Everyone's else's meh presence and ownership of presence within the story of KH3 ( Let's be real, other than Sora, Eraqus, Terra, Replika Riku and Roxas ( and Namine even?) , I'd go so far to say that everyone didn't necessarily have a satisfying moment of their own )
And then there's the usual bad writing, dialogues, plodding pace of how people speak, how some things are not clear in their purpose ( details on how power of waking works, impact towards Sora, etc etc ), which again, is typical for all KH games.
... BUT.
In terms of an overall experience? Other than Kairi ( whom even then I'm not all that salty about because I still loved her romantic moments with Sora and the part where she saved him during the Final World/Waking the Dead phase ), I was sufficiently satisfied enough with how everything turned out. The friends who suffered for so long reunited, the bad guys were defeated and by and large every main moment was earned, even if most of the moments were only 7 or 8 out of 10 in terms of effectiveness due to how rushed some moments were or didn't have the same level of potential impact had ( Aqua been playable, Riku having a explorable world to himself, Kairi and Sora were the ones in FW, etc etc )
Loved loved loved KH3 so much and I've never been more excited for the next KH game. ( yes, I'm more excited for KH4 than I am for KH3 )
My short summary of KH3 is this: "It's not everything it could've been and should've been, but it's everything it needed to be. And that is all it needs."