I usually take 2 days to get to maps or whatever, I don't mind it taking slower, I find the leveling interesting enough, I actually ID gear and shit which is horribly inefficient but I know once I get to maps I'll get bored pretty quick anyway. The thing is you can make it really fast if you know what you're doing but most people never learn how to run the leveling process fast. I could see them shortening some stuff but not that much, they'd have to rework leveling a lot to make it noticeably shorter by cutting content or whatever. The main thing they could do to make stuff faster on new rerolls is making lab league wide, so you do the shit once and then all your chars have lab unlocked(maybe keep the map lab locked). Just have an ascendency selection thing in the hideout or at the entrance in case people don't unlock their hideout for whatever reason and boom 6points right away.
But honestly that sounds like something only a minority of people care about, leveling being too slow. I guess a kinda valid complaint is not being able to level doing maps instead and maybe they should work on a system letting you do that.