Nah, Diablo 4 is much more fun when leveling from 1 to 70 or so. 70 - 100 is just doing the same things over and over with barely any rewards. It's the other way around there, leveling is fun, endgame is dogshit.

Usually "game starts at max level" is used for MMOs like WoW. Where all the leveling is seen as annoying bullshit fetch quests and at max level you do dungeons and raids.