I don't agree or disagree with the consequences part, but...
> sex leading to kids is hardly some unknown fact
Oh, I'd wish. There are people who still - in the 21st century - do not have like basic knowledge about sexual wellness and have very weird (and sometimes very dangerous) ideas about contraception, safety and risks of pregnancy. I mean, it's hard for any educated person to believe in this shit, but I've met or read some pretty insane opinions. Like people who genuinely believe really weird nonsense such as that virgins cannot get pregnant their first time. And they aren't malicious folks (well, maybe some are, of course) - just awfully misinformed.
Humanity is in a very weird place. On the one hand we've walked on the Moon and about to conquer nuclear fusion power, but on the other hand we've just climbed down from the trees and learned how to make a fire.