If the difficulty progression gets fixed, would you still think the lvl requirement is an unnecessary limitation?
That doesn't have to do with the difficulty per se, so yes.
It's about the freedom to choose. That doesn't mean there should be no requs after all or no improvements later on, just that players should have the freedom to plan skilling for themselves.
A game that got that working greatly was Guild Wars 1. Almost the whole game consisted of endgame content.
