While there are biological issues e.g. ability to give birth, I think social issues are more contributing to differences in position of women and men in the "Market"

1) Double standards in age difference. Couples with older man younger woman are more socially acceptable - increasing 'demand' for young women and competition for them.

2) Double standards for virginity and 'purity'. Many people value and praise women that stay virgin till marriage or long term relationships. While virgin men are considered to be losers. Slutshaming makes casual sex a bad deal for women, while virginshaming pushes men to seek sex.

3) Double standards for promiscuity. Men having a harem or just switching women often are considered to be high-value albeit jerks. Women having a harem are shamed as sluts without same ego boost.

4) Fixation on 'classic' PiV sex makes it a bad deal for women, as there is orgasm gap - men cum often, women sometimes have no orgasm. Research shows that lesbian women have more satisfaction than hetero women. Men could improve situation by being more altruistic in bedroom (going south more often for example). Lesbian women don't have penis, but they have tongue, fingers and toys - so men could do no worse than lesbian women.

5) Double standards against gays vs lesbians. Gays are hated more that makes bi men stay closeted, chose to act like hetero. While bi women has less pressure. So women have more choice of men, then men of women.

Bottom line: situation can be improved by ditching double standards. Do I miss something?