We need to put these restrictions on device, and hard socially punish anyone who breaks the pact. Like, our kids get phones with parental control, they get the whitelisted approved stuff only on those.
If I give my kid a general purpose computer with unsupervised access, I better be on top of that, especially if your kid is over. It's dangerous.
We are the adults here, we have to control the children for their own good, and frankly for our own good too whether said children belong to us or not. And we sure can, and we have always done so without eliminating vice, we just agree to exclude the children and punish any adult who breaks this pact. If we can't even control the children, we must be the most incapable idiot generations of all human history.
We do not need to give children access to the internet. There will be nothing of value to children published that can't be whitelisted inside of a week, and the delay of a week won't matter.
Conversely, we cannot afford to allow a comprehensive internet censorship regime for the adult public. It's too important for civil society to survive that every adult have unrestricted read and publish rights with every other adult. Therefore, the only reasonable move is to kick the children off of it.