We don't want to reverse the causes of declining birth rates.
1) Car culture (and trespassing culture) eradicated free roaming
areas for kids. This resulted in
2) parenting time is 20x higher than a few generations ago
because
3) children live in adult-curated boxes, under 24/7 adulting
because
4) they have no where to go. See 1.
In the US, a depopulated civilization would be allowed before we abandoned ~mandated driving.
Also in the US, some of the kids that are the most independent, roam the most, spend the least time in parental monitored boxes, are those in rural areas that are the most car dependent.