This implies 100% safety and freedom are possible. I prefer:
keep kids safe[r] online, and still have a [reasonably] open and free internet
What level of safety are we willing to give up, and what level of freedom as well?
I think things like zero knowledge proof of age can be a good balance, but all of this is going to be moot when parents just hand their devices to kids. Do we then force devices to passively biometric scan a user every 15 seconds or something?