If we expect Parents to treat Social Media like other unhealthy, dangerous, and highly addictive products, then that can never start with "just expect ignorant parents to all magically start doing something difficult, for no real reason".
It starts by banning kids from the internet, entirely. It starts with putting age restrictions on who can buy internet connected devices. It starts by arresting parents and teachers who hand pre-literacy kids an always-online iPad. It starts with an overwhelming propaganda campaign: Posters, Commercials, After-School Specials, D.A.R.E. officers, red ribbon week.
Then, ultimately, it still finishes with an age-gated internet where every adult is required to upload their extremely valuable personal information to for-profit companies, for free (With the added weight of being forced to agree to extreme ToS, like arbitration agreements).
So what do we do? I agree that the age of entry to the internet should match other vices (currently 21+ in the US, although really that should probably be 18+)...
It will never be acceptable for a single country's police state to extend across international borders, so... we just ban all of the UK and Australia from every web service until they get withdrawals and promise to stay nice? That could be a start.
But this whole situation in like 'freedom of speech' once you start picking and choosing what counts as "acceptable" speech, then suddenly you lose everything. You literally can't make everyone happy, because everything subjective is open to contradiction - and because there are freaks in the world who will never be satisfied by anything less than a complete global ban of everything.
Who gets a say? Do the Amish get to tell us what we are allowed to do? Where do you draw the line? You can't. Completely open is the only acceptable choice. But I still vote we start publicly mocking the parents who give their kids an ipad, and treat them like they just gave that kid a cigarette. Because seriously, they're ruining that kid.