One of the biggest functions of a patriarchy is males inserting themselves into areas of life that have nothing to do with them. Parenting, specifically being a “father”, is only one of these areas.
Women have been giving birth to babies since the beginning of humanity. Nature explicitly tells us who the mother is, it doesn’t matter who the father is. Why would it matter? Since males have made themselves dominant, they now control our reproduction.
So basically, paternity matters because males say that it does.
Males absolutely cannot stand to not be in control of women. After all, if women could control our own bodies, there wouldn’t be 7 billion people on the planet. Some of this overpopulation is because males restrict our access to birth control, abortion, education, etc. All of it is attributable to males and their obsessive need to dominate women.
The male capitalist system needs endless reproduction for war and to create an overabundance of low wage slaves, as well as prisoners, all to create profit for a few (usually white) males at the top of the income ladder.
Back to fatherhood. Males created marriage so that they could own a sexual, reproductive, domestic servant and they traded us back and forth as property. They wanted to insure that any children from their servant was their own, from their sperm. They have a disgust for children that don’t come from their own sperm.
Now, males cry no matter what is done. They want children, but they don’t actually want to do the work of raising them, or paying for raising them. A male will fuck his wife, she will get pregnant and have a baby, the male will largely ignore the child.
And when the woman decides to leave, then the male will complain about not wanting to pay child support (because we all know women get bigly rich on those payments, amirite), and complain about not getting custody. A well known fact is that males almost never ask for custody, but when they do bother to ask, they get it.
But if they ask for custody, then they can’t cry about not getting it. Males generally do not want the “woman’s work” of raising children. That’s why they won’t ask for it, because they might get it and they don’t actually want it. They love to play victim.
Males willingly have sex with women and a lot of them are not above using force and/or coercion. They use our reproductive capacity as a means of control, by (male governments) denying us reproductive freedom. Controlling our reproduction gives males the means to control us. Many women stay in horrible marriages because they can’t financially support themselves and their kids, due to very limited opportunities (in patriarchy, males always keep the best for themselves, this includes economic opportunities).
Males created religion as another tool of oppression, and they use it to keep women in their lower place, having babies. All of the religious texts value women having kids, as property of the male. And religions support women doing all of the work involved, while the dude watches football and goes to strip clubs.
Like with so many other things in a patriarchy, males control our bodies, for no other reason than to keep us submissive.
It’s not surprising that males don’t want to be involved with their kids. They see their children like they do their wife, which is as property. We are just another thing for them to own. Or they can ignore us, if we become more trouble than we are worth to them.
We will never be free until we have the basic right to control our own bodies. We have been waiting on males to allow us to have that right. So do we keep waiting? Or do we take what is rightfully ours?