Earlier quoted context omitted.
I have a different pet explanation from the other replies here, and I honestly don't get why it's not talked about more. Basically, our economic reality and expectations have come into conflict with biology and human lifespan. If you want a secured dignified life and basic prerequisites to starting a family, every year that takes a little longer. And these days, almost everyone wants that dignified middle class life…
So support should be provided for incentivizing younger parenthood then, like guaranteed tuition assistance per children born?
It needs to be a massive package of subsidies.
Children used to be a private good. Child-labor laws and the cost of raising kids flipped that. Children remain a public benefit, but that benefit is realized without paying for the cost. In essence, the cost of all prenatal, neonatal and pediatric healthcare; schooling; the opportunity cost in career and recreation the parents incur from having to raise kids; and the direct costs of feeding, clothing, nannying, et cetera children need to be directly subsidized, probably with a cash bonus on top.
In America this would probably be a ca. $50k/child benefit at the low end.