The effect? Less than ten thousand basic accounts existed in 2020, two years after their introduction. (source in Polish: https://serwisy.gazetaprawna.pl/finanse-osobiste/artykuly/14...)
[1] https://www.gov.uk/government/collections/basic-bank-account...
Things are a lot easier now with IBAN though, and a bank account is less of a hard requirement than it was 15 years ago.
Not sure I see a difference?
In most cases, unless you bounced a check (There is a separate system banks use on checks. It not tied to credit agencies.) you can get an account by walking in with any check, or money, though.
Many of our poor are stuck with Payday, with their outrageous fees.
Some homeless shelters offer p.o. boxes. Very few sadily.
All the Covid fun money blown out of tee shirt bazokas to fraudsters, and big healthy businesses; none went to people without an address. None.
ChexSystems is a credit agency. They just specialize in one data point (as of now).
https://europa.eu/youreurope/citizens/consumers/financial-pr...
Sadly, Boris fixed this for the UK.