Earlier quoted context omitted.
No let's not. Let's actually create and maintain a society. There are still places in the world where you and your family can literally fend for yourself against nature and rival gangs and so on if you're just super attached to the concept though, it's not like this option has been foreclosed.
This discussion is about the Internet. I.e. that we already have police and regulate in-person things like selling alcohol to minors, etc, is not a great argument in support of policing information .
But back to your original point, it's a pretty well-established function of government to protect the children within its borders from being harmed.