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.