I imagine nobody has this data, but presumably the correlation between birth control / women’s empowerment and lower birth rates is because maybe most humans were conceived unintentionally? Like, what’s the moral implications of most people being accidents, is that a massively taboo topic or is it just so uninteresting that nobody talks about it?
Not sure how it was elsewhere but where I live people usually had more kids because there were no retirement and once your body was weak you needed someone to provide for you. And more children = better chance of providing for their parents.