Cash transactions aren't free either. The merchant has to pay for security, transport, and typically suffers some "leakage". Depending on the type of business and location those can end up being even more expensive than payment card fees.

Yep, absolutely true. No free lunch.

Except that the bulk of the fees to the merchant are paid back out to cardholders in the form of rewards and cashback. So it's closer to a wash.

Someone seems to have computed the cash vs CC money flow: https://www.bostonfed.org/publications/public-policy-discuss...

"On average, each cash-using household pays $149 to card-using households and each card-using household receives $1,133 from cash users every year."

Visa still managed to make $15 billion in gross profit last year. Seems pretty significant to me.

On $7.4 trillion in volume. So about 0.2%.

I'd call that a lot.