> commanding a particular behaviour tends to encourage the opposite behaviour

No, it really doesn't. Look at Prohibition in America, or the "War on Drugs", or abstinence-only sex education.

What does tend to reduce harmful behavior is actual education about the risks and tackling the sources of those risks. In this case, that would look like addressing the addictiveness of these platforms, instead of, say, requiring an ID to use it. The latter will only encourage kids to go to other platforms, or bypass the ID checks, to say nothing of the privacy risks to everyone else.

Furthermore, the kids most in need of protection from those platforms, because their parents aren't protecting them, will likely just get their parents to ID them and let them on anyway.

> I specifically mentioned a culture disconnected from reality

In what way is it disconnected from reality? It seems to me that it is in fact exquisitely linked to reality by the very nature of a significant part of the population being on the Internet, as opposed to 20-30 years ago, where the culture was more of a subset of the general culture.

Also, I didn't "command" you to do anything. I suggested something. A "command" would look more like, say, a law saying you can't use certain websites because of your age. A "suggestion", on the other hand, might look like, say, schools educating kids about why certain websites are harmful to them.