Can someone catch me up how FB et al are not the ones responsible for age verification?

Is it lack of something similar to PKI for identify verification?

If we go back a few years and analyze the porn magazines that are sold in a gas station, it's not up to the magazine to ensure that the "reader" has the legal age.

So we delegated the responsibility twice, first the gas station attendant must check the age of the buyer and then, the buyer should check the age of any reader.

So now, who's the "gas station attendant" in our situation?

because there are other sites/apps online too, and it's better to decouple the "obtaining the verification" and the "presenting the verification"

and if sites and apps don't need to be in the loop for this they can't end up leaking all over the 'net

Why would you want every site on the internet to traffic in government IDs? This is by far the least bad out of all possible ways to implement age checking. The benefit of this is that it can short-circuit support for more onerous age verification. The writing has been on the wall for some time now: the era of completely unrestricted internet is coming to an end. The question is how awful will the new normal be? This implementation is a win all around, a complete nothingburger. We should be celebrating it, not fighting it tooth and nail.

The tech crowds utter derangement over this minor mandate is truly a sight to behold.