For individuals, cash clears at par: if you give me a $100 bill, then IÂm $100 richer and youÂre $100 poorer. No oneÂs going to jump in and charge a fee for facilitating the transaction. And if I then deposit the $100 bill into my checking account, once again I see the full amount appear on my statement.
But the fact that most people never get charged for cash transactions is corrosive, in its own way: it helps to impede the inevitable-yet-glacial move away from cash and towards more secure, easier, and cheaper forms of payments.
One at a time:
more secure
B.S. 1: Physical control over something - anything - is always the most secure. With cash, I have that. With a bankster's bits, I don't. Not to mention the non-trivial invasion of my privacy with respect to how I spend my money if I use anything other than cash.
easier
B.S. 2: Who refuses cash? What's easier than me handing over cash?
cheaper
B.S. 3: Cheaper for whom? There are no fees associated with my transaction if I use cash and many, many times, I get a discount for using cash. This is true for everything from AvGas to flowers for my wife.
This call for the end of cash smacks of "I've got an Econ/Business degree. I can't contribute anything real to society, so I'll charge a fee for everything productive that everyone else does. You gotta let me. It's better. And besides, how am I gonna pay for my Armani if you don't?"