Technology will win the day. Cards are much more than 3.5% efficient when you calculate in processing, theft, mistakes, bank deposits, accounting for cash, deterring and losing business from the majority of people who aren't carrying a bunch of Benjamin's in their wallet.
At a traditional sit-down restaurants, you usually don’t pay until you’re getting ready to skeedaddle.
By then, you definitely owe a debt.
Cash is legal tender for all debts public and private.
Let’s say you’ve got exact change, plus a cash tip, but—oops!—you see that the restaurant has a sign up: We don’t accept cash. Digital payments only.
Who wins?
Does the restaurant grudgingly take the cash, or do you put on an apron and start washing dishes?