> You may trust them with your money, but does not equate to trusting them with any other personal information.

How do you expect that they will give you your money when you walk in to a branch and ask for a withdrawal? Or that they'll replace a lost card? Surely you'd expect them to verify your identity.

They could verify your identity if you've given it to them.

But it would also be completely reasonable to authenticate the customer exclusively using mechanisms other than government ID. You can already make a withdrawal using your bank card and PIN. If you lose your card you could sign into their website using your password and request a new one etc.

Consider what happens if you lose your government ID. Your bank has much better ways to authenticate you at that point than the government does. Government ID has a major bootstrap problem, whereas patronizing a service doesn't because a new account with no money in it belongs to whoever is signing up for it regardless of who they are, and you can at that point give them a bank card and have them provide a password and email address etc. that allows you to identify them in subsequent transactions without ever needing their name.

Well, how do you expect a website to know that you are 18+?

The technical solution offered earlier was to have a trusted third-party only be willing to answer the "is this person 18+?" question. Of course, the same works for banks. The trusted third-party can answer "does this person own this account?" without needing to reveal to the bank any other information about you.

Now, that still leaves open the question of who you can trust. If you can trust a business run by people then that allows you to trust a bank, sure, but it also allows you to trust a tech company, so why not just give the tech company your ID and skip all that technical complexity? Understandably the broader idea presented earlier was that you cannot trust businesses operated by people, but then that includes banks, so...

For the sake of discussion, if we accept that technical solution and the need for a trusted third-party that is a business run by people, surely it should at least be a business that does nothing but offer profile trust to minimize the blast radius? For what reason would we want that business to have their hand in other activities like chat or banking?