>enemies level up with you.
I'm not entirely against the idea. Maybe have half of the enemies or at least certain enemies stop scale, or cease to scale after reaching a certain point. But what really sucks is this:
>you're never "underleveled" for anything, nothing is clearly way stronger than the player
That pushes things too far and makes the RPG world feel like its coddling the player too much, and this is on top of a "use whenever you like" difficulty slider.