You should take into consideration any disparity in staff effort between your payment methods. If a transaction takes twice as long, and/or is more error-prone when it’s cash, then there is a value the credit card network provides.

For me, using a credit card is way more convenient and I get “points”. The drawback, of course, is the surveillance that comes along with it. As a customer, I don’t like seeing two prices, and/or having to do math in my head on whether the points I receive will even out the extra cost. Don’t make your customers think too hard. They’ll start thinking about whether they even need the product. Reduce friction as much as possible for payments.