Except that this kind of age verification is not what "transnational corporations such as Facebook" is pushing for. In fact such a system is probably the worst for them: they can't use the token for tracking, and it can make it harder for them to target children because it is likely to come with further restrictions.What the tech giants want is OS level attestation. They want to control what you can install on your device, to me the thing to avoid at all costs. This is not it, this is an open source app that you can run anywhere.
The proposed solution is the closest you can get to one that is designed to protect kids more than to control online activities. The weakness of the system, where a determined kid can get through is a feature, not a bug! More than that and it becomes more about control and less about kids (who will get through no matter what).
I am not commenting on how necessary age verification is. Personally, I am all for a wide open internet but many people actually want to "protect the children". The argument wouldn't be used as a justification for surveillance laws if they didn't.