It’s also a fake one. As the other commenter said, the credit card system came about bec cash was very expensive to use for stores. They were passing along those costs to consumers, the fact that that’s now inverted by some stores (cash discounts) is only doable bec of the prevalence of credit cards.

Stores need to accept cash regardless, so there’s still some minimal added costs to using cash, but even with the offered discount it’s less than the credit cards...

however if stores stopped accepting credit cards they would quickly find themselves drowning in the same costs that credit cards were invented to avoid.