Someone on HN suggested parents set devices up for their kids and Browsers and OS's gate by age. I haven't really been able to fault this idea. State mandates verification and stuff like this makes me suspicious that this is much more than "protecting the children". More advocacy of alternative solutions please.
You make it an opt-in feature to "self-broadcast" that this device is being used by a minor. Solves 99% of the use cases. And for the remaining 1% — the really determined teenager — they'd never be stopped by this anyway. They'd social enginneer their way to access somehow.