That might be relavent if the item cost for using cash was reduced. I don’t think that has happened for a long time.
I’ve been a couple of places in the past year where they upcharged for a credit card purchase. And a lot of government offices do as well - around 3%. I have tried to start asking wait staff if the restaurant takes a 3% cut for processing tips on a card. A lot do now. And I try to tip in cash for those. Restaurant chain can eat the 3% for the bill; I don’t want to hurt someone that works hard for their tips.