It generally gets worked out with cash. Because the black market lacks the single most important thing for electronic transactions: trust.
As I said, there will come a time when cash no longer exists. As I see it - that’s inevitable. If someone disagrees and says that will never happen with “cash” - then that’s another matter and for another discussion.
The way I see people adapting — is as they have always adapted before and doing so in the context of their present society - according to the technological capabilities and the time period (which is yet in the future).
You give a picture of going backwards technologically speaking (in dealing with these things), while I’m saying that this kind if stuff will “move ahead” technologically speaking.