I was actually just thinking that; the succubi seem to actually be a menace to society considering they hospitalize people every other chapter or so, and a lot of the men they're sleeping with are scared of them. Why are they just allowed to roam around freely? Is this depicting a succubus-controlled society?
I don't think they dominate society yet. There seems to be some kind of acceptance or relatively balanced coexistence. For example, for better or worse, succubi got their own train cars; I'm inclined to believe this isn't a privilege, but a way to prevent molestation by the succubi. Succubi who milked or drained too much get a stigmatized with a tag on their tails.
Maybe the men who get drained or want to get drained think it's worth it (see all of our comment sections), so for the most part, they look the other way and don't advocate for change against the milkings.