Since I do not see a solution, and you see identifying children as a risk, what do you see as a solution for kids being in the same spaces as adults? Do you see a reasonable implementation to separate them, that doesn't have the "we know which accounts are children" problem? Maybe there's something in between?
Also, I think it's important to understand the life of a modern child, who's in front of a screen 7.5 hours a day on average [1], with that increasingly being social media, half having unrestricted access to the internet [2].
I hate government control/nanny state, but I think 5 year olds watching gore websites, watching other children die for fun, is probably not ok (I saw this at the dentist). People are really stupid, and many parents are really shitty. What do you do? Maybe nothing is the answer?
[1] https://www.aacap.org/AACAP/Families_and_Youth/Facts_for_Fam...
[2] https://fosi.org/parental-controls-for-online-safety-are-und...