The actual problem is not that kids are using group communications technology, it's that the network effect in public interaction has been captured by private companies with a perverse incentive to maximize engagement.
That's just as much of a problem for adults as for teenagers and the solution doesn't look anything like "ban people from using this category of thing" and instead looks something like "require interoperability/federation" so there isn't a central middle man sitting on the chokepoint who makes more money the more time people waste using the service.