Levelling isn’t the only progression though. There’s also a difference between the two. In D2, with most builds you’ll get no more power at all beyond level 90 as you’re just dumping into defensive skills at that point. In D4, as you can still pick up main stat nodes, you can get power all the way up to paragon 300. That in my opinion makes it worse than D2’s level progression.
Then there is the gear progression where this game is no where near in terms of D2. In D2 you can pick up forever pieces or really solid pieces of equipment that will hold until you find your BiS down the line early in the game. In D4 all gear is garbage until you get to max level. There is no sense of “hey I killed normal Diablo and got a pair of Magefists, these are my forever gloves!” or “I made a Lore helm or found a Peasant Crown, this will hold me over until I find a Shako.” With the way items are handled in D4, this feeling is literally impossible to achieve.