Genetic studies have revealed that, for most of human prehistory, almost all the offspring were the result of unions between a small sliver of men on one hand and every available uterus on the other.
In other words: We have a few g-g-g-g-g-g-grandfathers, but many g-g-g-g-g-g-grandmothers.
A fertile uterus was too valuable to waste. On the other hand, sperm is cheap!
Competition among men was stiff. Among women? Not so much. (At most: Competition for the best men.)
Don't want to "get into the weeds" with extreme cases, but: A horribly burnt (but otherwise reproductively fit) woman can still find some sperm. A horribly disfigured man will have to become a high-earner, a productive member of society. Unless he becomes a rapist.
Regards,
1/3 of all men can be traced as to having been the father to the general population. The rest of men were generally used as cannon fodder in order to keep the social order.