> It doesn't have to be your bank if you don't want,

"If I don't want"? I would get no choice at all about who it would be, because in practice the Web site (or whoever could put pressure on the Web site) would have all of the control over which issuers were or were not acceptable. Don't pretend that actual users would have any meaningful control over anything.

The sites, even as a (almost certainly captured and corrupt) consortium, wouldn't do the work to accept just any potentially trustworthy issuer. In fact they probably wouldn't even do the work to keep track of all the national governments that might issue such credentials. Nor would you get all national governments, all banks, all insurance companies, all cell phone carriers, all neighborhood busibodies, or all of any sufficiently large class of potentially "trustable" issuers to agree to become issuers. At least not without their attaching a whole bunch of unacceptable strings to the deal. What's in it for them, exactly?

Coordinating on certifying authorities is the fatal adoption problem for all systems like that. Even the X.509 CA infrastructure we have only exists because (a) it was set up when there were a lot fewer vested interests, and (b) it's very low effort, because it doesn't actually verify any facts at all about the certificate holder. The idea that you could get around that adoption problem while simultaneously preserving anything like privacy is just silly.

Furthermore, unless you use an attestation protocol that's zero-knowledge in the identity of the certifier, which OpenID is unlikely ever to specify, nor are either issuers or relying parties going to adopt this side of the heat death of the Universe, you as a user are still always giving up some information about your association with something.

Worse, even if you could in fact get such a system adopted, it would be a bad thing. Even if it worked. Even if it were totally zero-knowledge. Infrastructure built for "of adult age" verification will get applied to services that actively should not have such verification. Even more certainly, it will extended and used to discriminate on plenty of other characteristics. That discrimination will be imposed on services by governments and other pressuring entities, regardless of their own views about who they want to exclude.

And some of it will be discrimination you will think is wrong.

It's not a good idea to go around building infrastructure like that even if you can get it adopted and even if it's done "right". Which again no non-zero-knowledge system can claim to be anyway.

Counterproposal: "those types of social media platforms" get zero information about me other than the username I use to log in, which may or may not resemble the username I use anywhere else. Same for every other user. The false "need" to do age verification gets thrown on the trash heap where it belongs.

> Don't pretend that actual users would have any meaningful control over anything.

You do have control, you just don't like the option of control you have which is to forgo those social/porn sites altogether. You want to dictate to businesses and the government how to run their business or country laws that you want to use. And you can sometimes, if you get a large enough group to forgo their services over their policies, or to vote in the right people for your cause. You can also wail about it til the cows come home, or you can try and find working solutions that will BOTH guard privacy and allows a business to keep providing services by complying with laws that allow them to be in business in the first place. It's not black & white and it's not instant, it's incremental steps and it's slow and sometimes requires minor compromise that comes with being an Adult and finding Adult solutions. I'm not interested in dreaming about some fantasy of a libertarian Seasteading world. Been there done that got the t-shirt. I prefer finding solutions in the real world now.

> The false "need" to do age verification gets thrown on the trash heap where it belongs.

This is something you should send to your government that makes those rules. The businesses (that want to stay in compliance) follow the government rules given to them. The ones that ask for more are not forcing you against your will to be a part of it.

I get you don't like it, I don't care for it either; but again, you can throw a fit and pout about it - or try tofind workable solutions. This is what I choose to do even though I made the choice long ago to not use social media (except for this site and GitHub for work if you want to count those) porn sites or gambling or other nonsense. So all these things don't affect me since I don't go around signing up for or caring for all the time wasting brain rot(imo) things. But I am interested in solutions because I care about data privacy