Cash isn't free either (you need a float, security/insurance for the risk of theft, employee mistakes/theft, accounting costs to reconcile the days earnings). I

Cash isn't free either (you need a float, security/insurance for the risk of theft, employee mistakes/theft, accounting costs to reconcile the days earnings). It's just that these costs are often internalised by the company (I have no idea what the actual cost is compared to a credit card surcharge, but it's non-zero). Then (depending on your political views) there's the broader cost to society of tax-evasion that sometimes comes with cash payments (I'm not saying that cash is bad, but it's pretty clear that some businesses that are cash-only are avoiding tax and paying workers under-the-table, which has impacts both for government and the workers involved)