I suspect it depends on the kid. If they are naturally frugal and saving for things (and the household doesn't need the money), then why bother.

If they aren't frugal, and are otherwise suffering from lifestyle creep, then not charging them might be an injustice and setting them up for false expectations/never leaving home.

FYI, I was in the first group because my first job had pay cuts within 2 weeks, and then I discovered I basically spent minimal time at home anyway, so why pay more for it. Let me buy when I wanted to move out.