They think they’re more than a money pipe.

A competitor to MasterCard and Visa could show up with double their combined budget and do what they do to massively disrupt this particular industry. The average Joe would not give half a shit and continue paying for stuff with whatever card their bank gave them just like they always have.

The specific brand of payment processor a card uses is just not a thing people care about unless they have an Amex and that’s essentially because places don’t always take it.