In terms of future dating and marriage prospects... I can definitely see where one scenario is worse than the other.

Men sleep around with women (generally below his league) for easy sex until a woman comes along that checks all of his boxes physically and personality wise that makes being exclusive worth it. His future wife never has to feel insecure since she's most likely his best partner in nearly all aspects. She gets the gifts, the flowers, the dates, the dinners, and the small gestures (and of course sex)... while his hookups only got the sex part.

Women sleep with men they know they can never have... on repeat. If the guy is hot enough, he doesn't even need to take her out. She just goes over to his house for the first date. When it's finally time to settle down and/or re-calibrate her "true" league, it's with a man that nowhere near compares to her best sexual escapades and past sexual partners. If a woman just continually lets men play her and use her like this, she doesn't even respect herself and it indicates low intelligence. Why would anybody want someone with these characteristics?