Well, I'd say sex is significantly more prominent in a proper dystopian Cyberpunk setting than other sci-fi settings. Mostly because of the class separation and exclusive focus on urban life, where whores are common and highly visible.
Well, the main characters, at least the ones we are supposed to relate to, in cyberpunk are members of the criminal underworld and simultaneously social misfits and outcasts. I still argue the seediness in cyberpunk made its way into the genre because that seedy lifestyle is associated with people who live that way in the present. It adds color, flavor, and context. it's not a genre-defining element.
So, I agree that "sex on display" is a Cyberpunk thing, though it's obviously not exclusive to that setting. It doesn't matter if there are cities or places in real life with whores being prominent - because they're not prominent in most places. In Cyberpunk, they're pretty much everywhere you go - and that's what makes them part of the setting.
But, we don't go everywhere. We only go to the seedy underbelly, as the good doctor put it. And how would you describe Rome in decline, by the way? It seems to me that people of both sexes were owned, bought or sold for sex as a matter of routine.
Anyway, all this stuff people are saying about the cyberpunk genre is news to me. I never played the PnP roleplaying game so I'd venture a guess that's where it comes from. It doesn't, in my opinion, come from the classics of film and fiction. I am, or was, a big fan, and I would remember.
Anyway, it's all good if the game is good. And I certainly wouldn't complain about a less juvenile presentation of sex, so I didn't feel like the ideas about sex were coming from a horny teenager who'd never actually had any with anyone besides himself. Because, that gets pretty annoying.