Education/training/licensing/testing is required for so many professions and activities. Not parenting. Any animal can procreate. It is purely biological. How can the most important job there is require so little? Fertility is all you need. Why?
You said it yourself. We are biologically equipped to raise children. Part of this equipment is the ability to learn from how we were raised, and to respond to social cues regarding child-rearing. With modern technology (not necessarily gadgets, think books etc.) we have all the information available to us readily, to do the best job we can.
Some people get damaged, or are disabled from birth, and don't make good parents. We have systems in place to account for this, and where it's required, the right of people to raise their own children is removed. It's not a perfect system obviously, but the alternative of requiring training, testing, etc, to make people earn the privilege of raising children, puts our basic human rights in jeopardy.
Good parenting is usually learned by watching your own parents example, You bring up a good point since many children have only one parent due to losers in society,
I think if we did more to educate young adults to be independent and self sufficient in today's world, it would help them by the time they became parents.
There is no question there is a huge segment of the population that should not be having children. Breaks my heart to see a kid have to start off in a broken home.
