Off the top of my head I can only think of Lieberman and honestly the ESRB was a reasonable compromise.

It’s not impossible - parental controls can be used and school networks don’t HAVE to allow access to Porn Hub

Devices given to children can be configured to restrict access to unwanted things. Obviously, school networks already are.

The only uncontrollable thing would be kids seeing things via friends with less observant parents, but that is not a new thing.

No, it’s the not the same but there are options you’re ignoring.

We don’t need to kid-proof all of society. Adults deserve things like freedom and privacy and to not be treated like children.

Potential alternatives:

Guilded

Element

Revolt

Telegram

Mumble

Session