Comment by PinkSheep

> store just a checkbox that the person showed their ID and it was valid.

Doesn't work at scale. You get bribes, rogue employees, socially engineered employees. In the US, look up the articles about phone/SIM unlocks and SIM card copies. Russia has a problem with e-signatures, that most people have no idea about. It's possible to sell somebody's real estate with one of these. Loans granted just based on passport data. Neither politics nor media highlight these issues. Overall in this case your suggestion tries to handle the symptoms of the KYC requirement.

Here's a more extreme treatment: let people change their full legal name at will. Gender's already kinda possible.