If every country starts requiring that people provide official ID in order to "verify their age" to use social media, there will be no way to use any social media without associating the account with a legal identity.
This is horrible for democracy,
and should terrify everyone.
It doesn't matter if platforms use third-parties or not. It doesn't matter if they use some special encrypted code, the result is the same. This gatekeeps open discussions and government criticisms free from reprisals.
This is bad.
This is China "free-speech" bad.