As I understand it, the argument is: cash is valid payment for all debts public or private. But a sale isn’t a debt. The business that refuses your cash sale is refusing your business at the time of sale.

Apparently that explanation is even an FAQ on the fed website: https://www.federalreserve.gov/faqs/currency_12772.htm

NYC outlawed cashless operations after it started to become popular and the marginalized were increasingly locked out of everyday commerce. Hopefully it catches on in the rest of the US.

I didn't know this. Thanks for the tip.

https://www.nyc.gov/site/dca/consumers/Prohibition-of-Cashle...

You can even report establishments for refusing cash by category:

https://portal.311.nyc.gov/article/?kanumber=KA-03302