I don’t think saving them from spying is the main concern. Instead it’s the direct negative effects of the usage upon the kids that’s the concern. Not that age verification isn’t problematic

The possibly too subtle point of this article is that the spying is what makes the negative effects so powerful. Social media spies on what you are viewing and then sends you more of that, and send the info to other people so they can send you more of that too

Then ban underage smartphones altogether, that would probably make the single biggest improvement in child safety and mental health. Trying to police content is an utter waste of time.