EFF has a good write-up about zero-knowledge: https://www.eff.org/deeplinks/2025/07/zero-knowledge-proofs-...

> What ZKPs don’t do is mitigate verifier abuse or limit their requests, such as over-asking for information they don’t need or limiting the number of times they request your age over time. They don’t prevent websites or applications from collecting other kinds of observable personally identifiable information like your IP address or other device information while interacting with them.

Something like a cert chain, but it would need to be both simple to use and secure. Those two requirements are greatly at odds with each other.

Yes that's the idea, once you have the soul-bound eID the ZK part is trivial, but the eID with the guarantees I outlined is not at all trivial.