They fought tooth and nail against cash discounts OR credit surcharges and they finally lost. In some areas it's rampant that you get a pretty substantial discount - often 4 or 5%, better than cash-back - and many places post "cash prices".
You can get even more if you're willing to ride the hassle of the gift card train.
The credit card companies know people spend more if they use credit cards, and they turn around and sell that to the merchants.
Credit card companies are allowed to run cashback for using them.
All in the name of "consumer rights": https://www.gov.uk/government/publications/payment-surcharge...
Colorado law recently changed permitting merchants to pass on the actual cost of processing, except for cash, check and debit payments.
https://colorado.public.law/statutes/crs_5-2-212
This law overrides any prior contractual agreements with banks/processing companies that prohibit surcharges. This is previously how MasterCard and VISA coerced merchants into absorbing the processing fee, by contractually requiring credit same as cash pricing.