Well even in relationships these same considerations apply. A woman's investment in a relationship is higher since her biological clock is ticking, so to speak. She is most desirable in her teens and twenties and it falls off from there. Just ask who's chasing who after 35.

So, she will try to optimize her time in long term relationship with the best marriage / long term love partner prospect. That's why she cares about more than looks.

And what are men's considerations in long term relationships? It doesn't seem like they are just going along with the first woman who deems them worthy.

I guess there's a whole spectrum. Many men aren't interested in committing anymore. In general though men 21-40 are the chasers in the beginning and women are the chasers in the relationship.