> It's presumably harder to forge a cryptographic signature than paper documents?

Unless there is both serious pressure from the state and the population at large supports a massive increase in checking and being checked I struggle to see this working.

During the pandemic various countries experimented with mandating showing of QR codes to do stuff to "prove" compliance ... yet looking back on that, all it seems to have done is accelerate the erosion of trust in politicians and systems of government :/

Checking for right to work has been legally required for over a decade. Checks in the formal economy are now routine. Can sometimes be a nuisance, like for my friend who doesn't have a passport and his driving license was issued before those went photographic.