The problem with banning social media, is that it’s the main way teens are in touch. If all their friends are on Snapchat, then they’ll be left out if they don’t have it. Just like as an adult, I’d rather not have WhatsApp, but if I want to be involved in some family group chats, I have to have it. Banning them from the main way their friends communicate isn’t likely to seem reasonable to a teen, so they’ll probably find the easiest way to get around the ban.
I this is why I hope, and ultimately believe, that there will be a big culture change in the way that people manage their children's online use. Like the smoking in the car analogy above, I think we will look back horrified that we allowed our children unfettered access to social media and the internet.
I completely agree that it is a parent's business to fully understand every app their child uses, and to have rules in place against phones in bedrooms, especially overnight. We need to fully understand VPNs and other ways that kids can bypass pitiful parental controls.