They can't do the same things teenagers did before because the world has been growing more and more hostile to teenagers. More places have banned kids. We have these mosquito things making noises to drive teenagers away. It's become more difficult to get around without a car. Parents have become more helicoptery, not letting their kids out of the house. And "sorts itself out"? Here's what happens. Some asshole calls the cops on teenagers just hanging out. The cops, with nothing better to do than harass innocent people, show up and chase them away. Now those teenagers don't feel safe going back there, because they don't wanna get cops coming after them. Or maybe the cops don't stop at chasing the kids off! Maybe they get arrested for "loitering" or some nonsense. Maybe they get accused of dealing drugs because teenagers hanging around is strange and suspicious, and the cops love to frame innocent people. Cops getting called isn't some silly and frivilous thing.