Even though mother and child mortality is minimized, there are 999 life-altering things that can go wrong.
Take the simplest ones: what % of the population has the kind of mental illness that’ll destroy your relationship with them? E.g. borderline personality, sociopaths, etc.
Easily 5% or more.
That alone is a 1 in 20 chance of your kid ruining a significant portion of your life, not to mention you bringing a kid into the world with an inevitably ruined life.
And then there’s physical disability, not to mention financial burden.
It’s not worth it.
I’m very glad other people roll those dice: I’m happy to live in a populated world. But I don’t touch the dice myself.