How Come the Human Race is not Extinct?

I was thinking about how fragile young children are. Everything they do is irrational, and it's our job to teach them so they can learn and experience the world around them.

But man, they are so fragile I sometimes wonder how come our race is not extinct. Children are the best magnets to diseases and viruses, and it doesn't help that they put everything they find in their mouths, be it a clean sock, or some unknown thing in a pile of suspicious dust in a corner. I guess only a minority of illnesses can be fatal.

What children put in their mouths can also be round, coincidentally exactly the same size as their throats. They can suffocate and scare their parents to death. Evolution has not a role to play in this, because in the past, the only things they could suffocate on would be some berries and small rocks. With human evolution stopped, children will never know innately about this danger.

Acting irrationally, and doing things without the ability to think before, can easily lead to injuries to themselves and others. Drinking anything that look like juice is particularly bad, when you look at what's under the sink. Parents are not omnipresent, and accidents do happen (unfortunately). Children play in the stairs, cross the street without looking, and do all sort of things that they stop doing at a greater age, after they learn by experience.

I guess we can all be grateful that only a fraction of what children do lead to a tragedy, or else we wouldn't be there, would we?