My understanding here is that Mastercard/Visa aren't charging customers, they are charging vendors who take that payment. Some vendors build that into the price of items, some eat the cost, some do indeed pass the cost to the consumer. But the latter is rare except for small businesses (which this case seems focused on).

TBH I'm suprised they even bothered with an anti-steer approach. Visa/Mastecard are about as objective a duopoly as we can get in the world of financial transactions. They can control entire industries because removing the vendors' ability to take their cards is a death kneel.