I agree with all you say, I would just add that that women might have higher standards than men. Maybe not, but I think it would make sense. Effort plays a huge role of course, but it does seem like lacking beauty could have gotten women killed more than it got men killed (just like lacking upper body strenght probably got men killed more often than women).
Also, an economist called Catherine Hakim had a good theory about a “sexual demand gap” : although sexual desire in young people is similar, it declines more in women after they have children then it does in men, so there are more “horny” guys than horny women when you sum all ages together. That might create a higher demand which fuels the illusion of women being more attractive