This doesn't address the wider array of age-verification related problems that people want to solve, like social media where age verification is needed to police interactions between users.
I could be misunderstanding the context but to me that sounds like a moderation issue assuming we even want small children on social media in the first place. There should probably be a dedicated child-safe social media site that limits what communication can take place for small children and has severe punishments for adults pretending to be children for the purposes of grooming.
This is assuming children should be on social media at all, which I for one would debate.
Such censorship shouldn't exist in the first place.