I believe so, but it could also vary state-to-state.

Cash discounting was blanket permitted in all 50 states under Durbin. [1] It also de facto invalidated any clause in a merchant agreement that precluded this practice.

[1] https://www.atlantafed.org/blogs/take-on-payments/2018/04/30...

Only places I've ever seen do this are gas stations. And I've calculated the discount, I've never seen it be more than the cashback I get on gas purchases from my card. Usually, it is way less. And that is without getting into losing the time saving/convenience of paying at the pump.