And the cost of staff pocketing some of it, and the cost times risk of it being stolen, and the psychological impact to employees of the store being worth robbing...
You forgot cash pickup and delivery costs for big stores or sending two employees to the bank with the day’s revenue (that’s the cost a lot of cash-only merchants in Germany usually don’t calculate for). Also don’t forget the counting of the day’s cash, two employees 30 minutes each.
https://www.rbcroyalbank.com/business/accounts/flex-choice-b...
Which is ~0.25%. Presumably a cash register also has some amortization on it.