It's too late and never about children, simply deeper forms of data harvesting and surveillance. What makes me extremely sad and concerned is that more recent generations simply have no idea or expectation of privacy online anymore. There will never be more of a fight against all this Orwellian behavior.
I live in an area that has been declared among the safest in America. Two months ago a 17 year old girl from our city disappeared. Turns out she had been being groomed for a year over Discord and in Roblox by a 39 year old the next state over. He eventually convinced her to let him pick her up, after which he filmed himself having sex with her, killed her, and then dismembered her body. He apparently was grooming oth…
Well, your example wouldn't be solved by age verification in any way. They could still legally access Roblox or a discord private chat (or even another private chat method) after this law.
So the example show how it is about irrational fear and not protection in any way.
And this is an tragic edge case, if you want to take this kind of edge case in consideration, you also have to take in consideration what the age verification would imply as tragic edge case.