Time and again, where people have adequate (not government supplied and metered) health care, property and economic rights, they just don’t have many kids.
Kids are expensive.
Just about every woman wants a baby, and just about every man wants a legacy, but for most people, 2 is enough, not 8. That’s not to say 8 is too many. In a free society, people can have as many kids as they want, but given normal middle class circumstances, 2 is the norm. And many people have none, sadly.
According to Swedish health professor and statistician Hans Rosling, the population will rise to 11 billion by the end this century, and then go down.
Watch:
https://www.youtube.com/watch?v=hVimVzgtD6w
https://www.youtube.com/watch?v=2LyzBoHo5EI&t=27s
https://www.youtube.com/watch?v=FACK2knC08E