Actually, the problem with this whole check is that not children, but adults will be forced to de-anonymize at the legal level in order to prove that you are over 14+(16, 18, 21+) years old. Beyond the legal level, intelligence agencies already know everything about extrajudicial methods of controlling the Internet.
There is only one way to deal with this - don't visit social networks like me. But if the social hamsters really want to, even the consequences of legal de-anonymization will not stop them.
You people are tightening the noose around your own neck, allowing you to build new levels of control.
As for children, I strongly support their isolation from social networks. They have nothing to do there.