Are you saying parents would choose not to block it, or children would get around it? Like you say people want to block it, but currently it's very hard while allowing access to Google and other resources, or it's easy to get around. Why does this require server verification?
replyFor example, all devices could require your ZKP ID attestation to be usable unfiltered. Then the relevant apps/sites would be equally inaccessible to children. And then you remove the ZKP ID attestation because the device owner (parent, school, etc) already knows when the user is a child.
The on the ground reality is that now most social interactions at schools and the content for those interactions happen on social media and apps/private chat rooms. If you don’t have a smartphone or not using those platforms, you’re just left out. There’s going to be serious social cohesion issues for the kids that don’t have access to them. It’s also going to cause continuous pressure throughout your schooling years to circumvent whatever restrictions your parents are putting on and to be in constant conflict with them because of that pressure. That’s life altering stuff.
replyZKP ID would work but that’s essentially deanonymization because you have to provide your ID to someone though no one has total information. Also just checking for its absence doesn’t work because that’s opt in and less than 5% of parents would do it. Every individual, irrespective of age would have to have a valid one.