You haven't outlined why this is a problem? Population growth overshot with expanding abundance and developed countries are now normalizing to a more sustainable level.
when you had to farm to eat, you needed more farm hands. And lots would die young, or from simple injuries and diseases.
better to have a couple more extra kids in case some of them croak at 8 or 13. with the plus side that now you have extra hands to work on the farm / shop / artisanal cooperage, etc.
