I don’t think kids usually go buy their own devices though, so really this needs to be handled on device setup, which I believe apple phones, at least, already

I don’t think kids usually go buy their own devices though, so really this needs to be handled on device setup, which I believe apple phones, at least, already do now. The ID check seems wrong then; if the parent wants to allow their kid to use the device unrestricted then that’s their right.