This is already in place. After EQ was breached, I wasn't sure who to go to, to change my Date of Birth, so it's still the same. :|

There is already a lot of truly immutable and practically immutable data that's tracked.

The other issue is the courts have dictated that you don't own your own biometrics. Phone locked with face or fingerprint? They can get a court order that allows them to force unlock it.

A pin code is considered more secure, because it can't be force bypassed, like biometrics.