The confusing part of this is that they think this is a teen issue, like they see adults loitering everywhere. There's logic behind why you don't see them doing it because they have their own homes to hang out at but if four adults were hanging out by the door of a shop they wouldn't get special treatment.

In most places adults gather outside of their homes you also need to pay for outside of parks

Where are kids banned from hanging out? When did this happen???

This idea is called a "Third Place". Your first place is home, the second place is work, and the third place is another place that isn't the first 2. There used to be more of these like malls, plazas, parks, and others. In the last few decades, these places have gone away, had funding cut, or otherwise died. And like OP is saying, there are places that have been created to fill this gap, but they have been monetized :(

I realized that I treated Reddit as a third place. It was somewhere I felt like a community existed that I could talk to people and just hang out. It wouldn't surprise me if people felt the same about Tik Tok or Facebook. So when one of those places is threatening to leave, it makes sense they feel there will be a void created.

Not sure what a good solution would be as this is a complicated issue.