If the point were to improve on the mental health of kids there are countless underfunded public programs. Especially in the US, social support programs like food, healthcare basic and mental, actual physical public spaces for kids, arts in curriculum, etc.
Conversely, I don’t agree with the way some other countries are going about it. Especially the UK with the abysmal way they have physically policed online speech by adults. Incredibly sad to see police prioritise non-violent “speech crimes” because they’re too scaredy-cat to tackle actual violent crime.
There is a reasonable answer to be found, if we're willing to be inventive. It shouldn’t be beyond the imagination of cryptography experts to design a system where only governments can issue an age identification certificate, which individuals can use to generate verifiable proof of age tokens. But where the tokens can’t be used by the government to identify the individual.
The government shouldn't infringe on my right to bear arms, mass shooting is a mental health issue anyways, oh but we can't really fund mental health support because my tax shouldn't go towards helping those who put themselves in that situation. Que the same argument for privacy on the internet.
You can't have your cake and eat it too. If you can't trust the government, then work towards healing it, restructuring it, overhauling it. Subverting the government is such antisocial behaviour, very criminal like.