> we might as well be arguing about what we should be doing when aliens arrive, since they might arrive in the future, too.

Did aliens land in multiple states already? Strawman deflections aside, scanning is the natural evolution and has already happened across multiple kinds of exchange (money markers, various ids, various phone apps, etc). Government issue has a benefit of an independent verification system. It's super expensive for various government agencies to integrate into businesses. Constituents and businesses don't want that, leading to a much more comfortable adversarial relationship, imo.