Monster Hunter is a great example of a series with quality sequels. They always add some new, interesting mechanics, trim the fat from the previous iteration, and add new content while still keeping the core gameplay exactly the same. There have been some exceptions, but generally every MH game before they split the dev teams had been an improvement on the last. Even when they cut the swimming from 3U to 4. It was a system that most players didn’t enjoy, and 4 had so many great new additions like mounting that it hardly felt like anything was missing.
That said, one of the main criticisms you’ll hear from players is the “ultimate” edition being the same game with just some new hunts tacked on. Or even that the base version isn’t worth it and the ultimate version is the “real” game. Nowadays they do expansions instead, which I think players generally find more palatable
I’ve got to recommend Monster Hunter Freedom Unite. One of the most legendary games in the series for its sheer amount of content. It might feel a bit dated if you’ve played World or Rise, but still good