Hell raising kids in the 60s & 70s is a lot less work. You could send the kids off into the neighborhood to play with all the other kids and only interact with them when they had issues. Otherwise they would rather be out exploring the local woods or streets with all the other kids, and family being around to help out.
Now with the legal necessity of 24/7 adult supervision before they are 12, that is gone and as a result you have helicopter parenting making it a shit ton more work to do.
It's a form of demographic debt. By increasing the workforce #, you decrease the amount of kids people have (because they can't afford the time to have many kids) but increase total GDP until you pay the piper later with decrease reproduction rates and more seniors that the economically productive.
I also want to say that it's not necessarily good to have one person be the house spouse only and then come out the other end with no skills. That can be a trap and be especially bad if a divorce or other split up happens, not to mention when your a bored empty nester.
It's good to be have some skilled profession to come back to. Kids are time consuming from the start, but they start spending less and less time with you as they get older.
For an alternative perspective that refutes a bit of this, maybe meat is actually the more environmentally healthy and human healthy way of going about things?