Earlier quoted context omitted.
Additionally, children are expected and virtually required to be supervised 24/7 for the first 14-ish years. Kicking kids out to play like Just William while Mrs Brown goes to the Women's Institute all afternoon is now called neglect and child abuse.
Part of it was older kids looking after younger ones which just isn't a thing anymore as far as I can tell.
And if it goes wrong you can get prosecuted for that and/or dragged through public infamy. In fact even if it doesn't go wrong you can probably still be reported for it.
Which is presumably a very good thing for child safety, but obviously there are these downstream effects.
Another similar thought was the theory that car seat laws act to cap more families at two children because with three, you can't legally fit both parents and the children into a normal car.