You don't need to show your ID to go into the store and buy something else though, so why would this provide any sort of precedent for "you can't use the internet for literally anything on this device without proving your age"?

In many areas, this is left up to the parents - minors can't buy alcohol at stores, but parents are legally allowed to give alcohol to their children to drink.

An analogous good implementation of age restriction is that one must show their ID to buy an unrestricted device if they look too young.

They can't be tracked, as long as the devices are in randomly sorted identical boxes. Of course someone can buy a device and give it to a kid, but that's already possible with alcohol (and legal if it's their kid).

> Even in the offline world that is not the case. Ex. Alkohol sales

I bought a beer yesterday and shared it with our 16 year-old, and I shared some wine with him this evening.

How does that not come under "parental responsibility"?