At a national level, it’s hard to see how (assuming the country grows enough food and has other basic necessities) it is possible for the country to be “unable to afford” children, Baumol be damned.
Just because we have more billionaires than ever doesn’t mean a lot people aren’t struggling. Back in the day, someone could pay for a mortgage, wife, and kids with one job without a college degree. Where I live, that’s not happening.