They create uncertainty in whether a man's actually the father or a cuckold, they granted women undue influence in the structure of early society since they tended to stay at home and organize home life and raise the children. It's harder being a single herder without somebody organizing the household that provides food, shelter, clothing, and heat.
Hence matriarchies are posited as the earliest form of human social structure. Oddly, they're always romanticized as good.
Arguably, early societies, in which children are scarce, were organized around childbearing--not just the women's lifestyle, but also the men's. Lots of training of children, getting extra food for children, protecting the offspring against intraclan, intratribal rivalries. On top of that you have the adults all competing for their own selfish interests. Recently men were better at it than women, if only because it's likely women were more interested in the children they invested so much time with and bonded with. (My family was the opposite: My mother worked for herself and took care of herself; my father worked to feed me and provide for me. It's no prettier when the mother is a selfish sexist racist ogre than when the man is. It's just less stereotypical and so can be ignored as a possible variant to be considered in an argument.)
The biggest change since the Paleolithic is that currently, for many people, children are commodities. You need a certain level of luxury for that to be the case and even places like Afghanistan have long since reached that level.