One important feature of a legal ID is that it's hard to copy, so attestation from the hardware storage would have to be basically mandatory.

But yeah, the user could have a choice to this extent.

You can attest that cryptographic key material is safely stored without attesting that their operating system and software running on it is all government-approved.

That's what smartcards like Yubikey do, my government certificate is on it and it can't be exported. They could attest that but beyond that, the operating system of the host device is none of their business.

> You can attest that cryptographic key material is safely stored without attesting that their operating system and software running on it is all government-approved.

There's no proper way of doing so on Android.

Some countries, like Estonia, are providing their own SIMs to solve this problem. That indeed works. Unfortunately phones are being made that are eSIM-only and certifying eSIMs to the same EAL level is near-impossible.