Doing this without the parents on board does not work. Kids can lie about their birthdate by a few years. Facial age estimation has error bars of like 5 years and many teens don't have any ID. Younger kids use a parent's phone. Many are not supervised by parents or have parents who are complicit/encouraging in getting them more access. Oh you could be famous! But it is clear that more persistent identifiers online will make anonymity much more difficult for everyone else.
Parents are massively on board.
And they are probably moving to a system where you need to link your device with a government issued cryptographic ID (i.e. passport) using zero knowledge proofs. With a system that ensures an identity can only be installed on one device at a time.
This means a parent would have to give up all social media accounts and chat apps on their own phone, in order to give their identity to their kids.
Can't read the article, paywalled. But what makes you think the parents would not be on board?
You gotta start somewhere.