What’s fascinating (apart from the sound those things made is still in my head) is that the very nature of the technology meant who could and could not get credit varied. At first (1950 diners card onwards) only well off could use it at limited establishments (ie restaurants) and they would postal deliver lists of cars - initially white lists of valid card owners and later hot lists of delinquent card owners. Stick your privacy issues in the restaurant food bin there!

Calling a call centre to verify every transaction is too expensive so only purchases over certain limits came in following BofA/Visa - and that stated that way till the late eighties when larger stores started using back office to talk to Visa network etc. but even so the ability to do live updates and verification was too much and there were weird cacheing tricks

So banks could easily approve or be liable for transactions they would prefer not to approve - so they only gave credit to the rich at first, and then to those who paid back regularly. This info was shared and became credit reference agencies - because the credit card companies shared it initially like casinos but the abuse and mistakes brought legislation

I think what i am saying is our consumer credit culture was not designed, it just grew.