What's wrong with EU age verification? Part II

My EU age verification post triggered a long debate on lobste.rs. Here are the points I found most worth engaging with. I’ve probably missed some, the discussion was really long, and I’ve also received feedback though other channels. I will post again if I feel there’s more to share on the topic. Favoring the incumbents A point I missed the first time. In the EU design, an authority issues me an attestation that I'm of legal age; it lands in my digital wallet. When a site needs to check, the wallet generates a zero-knowledge proof that it holds the attestation, without disclosing it. With most wallets, we assume the user protects their credential — nobody voluntarily leaks the password to a wallet holding money for example. Age verification inverts this: the user is part of the threat model. Some users, given the chance, will happily share their "over 18" attestation with a minor. So the system can't trust the user. It has to trust the device or the wallet instead. And for the issuer…