Comment by fruitworks

there are multiple credit card companies, but only 3 big payment systems: Europay, Mastercard, Visa. that is the protocol: a triopoly that controls everything and then a handful of companies that wrap the same product and can't fundamentally change it.

Not unlike generic laptops that are made by OEMs in taiwan and resold by dell, and whatever small company.

"Solving" the problem of signing up clients and vendors at the same time is a different problem for the companies. They benefit from the vendor lock-in. The "solution" is to establish a monopoly