people aren't in the caves because 90% of the population is already capped and woc'ed, and the other 10% just started new characters and are still in the sewers/mb.

also, the caves aren't used as much because even if you would survive, the xp in regants is way better than in the caves.

imho really difficult areas like the swamp caves should exist purely for the challenge. I go there every few weeks just for the challenge, with a ppu and two or three clannies.

That said, there should be a bit more variety in leveling spots, as current it's sewers - > mb bunker - > regants, with possibly el farid in between.