how/why did children survive all those generations ago where these dangerous things have existed, and all of a sudden, parents are now powerless and unable to parent?
You had to go to a special store where an adult checked your age.
But I guess the better option would be to give parents the propper tools. For example every OS could have the option to set up a child account, that gives the age range to the app store / website the user visits. And the app store owner and website owner (of a certain size? Not sure) have to implement it. Just like store owners can't sell alcohol or porn mags to underage customers.
They didn't survive, they died:
https://www.statista.com/statistics/1041714/united-kingdom-a...