China will probably be the only country that solves this.
This is an outstanding article on the subject: https://www.newyorker.com/magazine/2025/03/03/the-population...
In the US, parenting time is up 20-fold, from a few hours per week to 24/7 adulting.
Companion to that is that free-range land has shrunk from many sq/mi to a few sq/yds. Car culture and trespassing culture has eliminated the irreplaceable environments where adult-free, peer time nurtured mental health and abilities.
As near as I can tell, parenting and childhood is irreparably broken in the US.
We certainly seem incapable of recalling what sustainable parenting once looked like.
On rare occasion someone will recall that kids once roamed all over. Maybe that gets connected to less mental health issues. Either way it's all forgotten moments later.
Today kids live entirely in adult curated, adult populated boxes. I'm not inclined to blame ipads for that.
The point of OP and what people don't get is that it's far easier to shift policies to brace for tough situations when you have a uniparty system and you're willing to make sacrifices. No 4 year administration is in any way incentivised to enact policies that only become effective after the next election. Note that I'm not saying that undemocratic systems are the solution.
Most wealthy countries have already solved it: immigration.