This might be an unpopular take, but I remember being that age and having to jump through so many hoops to access the sites I wanted to access, and I swore to myself I would defend children's right to exist online. I'm 35 now. My opinion hasn't changed.
The regulations ask websites not to target advertising to children. Websites don't like that because advertising is their main means of profiting or breaking even, so they try to pull their site offline for minors, and limit their ability to communicate with others. COPPA doesn't require that you limit the ability for minors to communicate with others, but websites err on the side of caution because of the very real threat of pedophiles.
Children age 12-ish are bored out of their minds, and a lot of them are really smart and would contribute to the internet in a positive way. See the story of Aaron Swartz. He contributed so much to open software before he was even 16.
I think this is also true if adults, but I think kids are particularly susceptible to unhealthy habits / addictions around mass media systems.
Consuming an infinite amount of media is positively wholesome by comparison.
As for work, I have had a hard time leaving jobs, because to me that also means leaving the people I work with. I guess my office life is similar to my high school life in the sense that I actually like(d) the people around me.
Where it breaks down, is when you get a whole ecosystem populated entirely by kids and those trying to make money off of them.
However, social media ever since feeds and the "like" button are an entirely different beast which is addicting, dehumanizing, and antisocial - preventing kids from developing socially.
It is NOT SOCIALIZATION to talk to people on the internet. Your brain simply does not treat it the same way.
Kids are fine interacting in person at school and other public places. They don't need this social media bullshit, and even private messaging systems like AIM or MSN aren't really that great.
And a person of any age can drive a car on private property.