I think part of that is also that KH3 actually sucks compared to KH2, and even KH1 in some areas. Yeah, KH3 is flashy, but the story beats were just awful compared to the previous numerical games. I still haven’t played through the plethora of tie in games, simply because I think the director lost the fucking plot after KH2.
I also feel like Ultimate is the pinnacle of the formula. Besides the mods that people are making for it, you just can’t get better than Ultimate in my opinion!