I think you've nailed it and it's kind of depressing in a way since there were a lot of things kids were part of just a few decades ago. The local football group, the bunch that gathered together to watch a TV show at one guys house that would air at 7:30 pm on a weekend, the circle of cousins kids would hang out with during a stretch of holidays, the circle of people who they'd meet regularly during a congregational prayers, etc. etc.

These things are as missing as they're necessary in kids' lives and (non-mainstream?) music gives people some semblance of community that has a stabilizing effect.

The Discord "communities" don't have the same effect unless the group actually meets in person regularly.