My attempt at _a_ solution isn't _THE_ solution; but it seems like there's legitimately something around leveraging existing KYC infra that could get a solid 98 out of 100 - and can realistically be implemented in a realistic timeframe.
If I'm AYLO and have been cut off from 1/3 of the U.S. for the last 18 months, I'm contacting every lawyer, cryptographer, and engineer I can get my hands on to try and get _anything_ out of this concept or ones like it.
1. 7 million (2020) has no proper ID [0].
2. 120 million struggle with reading [1], and you can assume at least 7 million realistically can't read.
3. Banks already do identity verification across the world, even on behalf of the governments themselves.
I see many challenges in what OP is proposing, but banking adoption across population is not one of them.
[0] https://www.voteriders.org/voter-id-research/
[1] https://www.apmresearchlab.org/10x-adult-literacy