We will lose all anonymity. If we are cashless and everything is on a credit card or debit card transaction somewhere, it will be possible for marketers and government to compile very detailed dossiers on how you spend your money.
Kids’ lemonade stands (but many cities are legislating them out of business anyway)
I just recalled a Candid Camera type show where a kid had a lemonade stand but would only take charge cards. It was hilarious.