The people who actually pays for this are cash and debit card users. Because there is a single price for merchants, the merchant charges marginally higher to cover the cost of the transactions. Credit card users are less impacted because credit card companies convert a portion of the revenue into incentives for their card users to continue using their cards. (Chase Sapphire Reserve anyone?)

Here's a good paper that goes into this: https://www.bostonfed.org/publications/public-policy-discuss...

From the abstract: 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.