They know it. That is why many men who want casual sex say in their profiles "open to relationship". They create false hope to get the sex they want. And it has been like this for generations, men making promises of marriage only to walk away after they get what they want. It is not new.

The difference now is that women who aren't virgins are no longer "ruined". While there is still slut shaming, they have the opportunity to explore more before they settle in a relationship. To learn more about themselves and what they want in a partner. Or if they want a partner at all.

I know a woman who become a mom through artificial insemination and has lots of casual sex. She is completely happy and fulfilled. She has a cheerful daughter, a family, friends and since she really enjoys sex, whenever she wants (and her daughter doesn't need her), she goes and has casual sex. And since her daughter is waiting at home, she is the one who leaves. That works for her. No regrets or emptiness. But when she was in a relationship with a controlling man, she wasn't happy. She felt trapped (rightfully).

All the assuptions you made about what women want are basically what traditional women used to be told to want. It worked for a few. But know that women can actually choose for themselves opposed to when it was their father who actually choose, we are seeing lots of different choices and different results. Sure, some women would make mistakes, marry, divorce and marry again or go on single. Some women would take their time and would find out that the "brief time span to find a partner", wasn't brief at all, that you can meet your someone at 50s, 60s or even at 80s.

Look around there are lots of different stories and takes on love. Different women want different things. And they can even enjoy plenty of casual sex in their youth and settle with one man latter and that be the best for them because at some point they just wanna have fun and at other they meet someone they want to be with all the time. That is life.