Persona 5 definitely spoiled some people lmao. Do people realize just how big an 80 hour KH game would be? (Assuming we're talking about the critical path)Im pretty sure some people believed KH3's main story would be something like 80 hours long like Dragon Quest or Tales Of. Most KH games the story clocks out at 15-20 hours so KH3 is in fact double the length of previous KH games
Length doesn't equal greatness. Naruto Shippuden ended on 400+ so episodes, is that show a masterpiece? No, but it's still a great anime with fillers and all. Conversely, look at Gurren Lagann. 27 episodes, and that anime is in the upper echelon. Point is, not every video game can be a Persona 5 (or any of the previous), and not every anime can be One Piece, with length AND quality. What's most important is how the story is told, and of course I'd love it if KH3 was a long game, but that comes with pacing issues and potential filler.
You don't need 80 hours to tell a great story, Nier Automata took me 30 hours, and look at how amazing the story it is. Again, would've liked it to be longer, but that would've come at a cost. Spider-Man took me 20-24 hours (with side quests), and it's an amazing game.
If the the story is stellar, the duration won't matter. What matters most is the experience, and people here are ruining it for themselves by whining before the game even comes out officially. But oh well! I'm more than content, so that's what matters to me in the end.