If your personal data is on chain, it’s there forever on the publishing. That is to say, instead of just de-identify it a little bit, control the privacy budget, that simply doesn’t work if you want to interoperate or federate. You have to simply store no personal data to begin with, and to adopt an entirely zero-knowledge idea, where not just the data, even the metadata, the operator doesn’t know a thing about, so they become just the intermediaries without any lock-in power.