And just enough of them have been ‘tricked’ by religion or culture or noblesse oblige, etc. to keep post-agrarian civilization going.
But also there is a huge number of people that have children that are poorly prepared for net-positive contribution, and they receive almost all of the structural incentives allotted to parents.
There are actually structural disincentives to intensive parenting, like triple-taxation levied on parents that hire professional childcare. It would be easy to make this fully-deductible, but, like I said, the people at the top don’t like competition. Also consider that Social Security is just generational transfer payment, so it might make sense to pay some portion of taxes up the family tree, as well as deducting for any social burden like welfare and imprisonment. You do well, you get rewarded, you screw up, you pay, and there’s a big element of chance, just like anything in real life.
But I really would like to know, do you want less total number of children in the world, or do you want more childless leisure-class adults, or are you genuinely trying to warn people that their lives will get a lot harder with children?
It seems to me that you’re not wrong in the small sense, but in the grand scheme, we still need those hero parents out there.