I agree with the OP. Lower XP gains/increasing leveling requeriments would help the game.
E.g. finishing Act 1 not borderline 6th to 7th, but 4th to 5th? Pushing 6th max?
The Creche gives IMO insane quantity of points.
I am aware that not everybody maximises XP gains, but a remedy could be boosting everybody to 6th when Starting Act2?