I don't buy the reasoning as to how Visa built a moat. From the WSJ article linked in the article:
>> Visa offered to pay Costco $150 million. One condition of the deal: Costco would not do a credit-card deal with a bank that had its own network, according to the people familiar with the matter and the court filings. That shut out Chase. Visa also offered Costco an exclusive discount on the interchange fees the store pays when someone makes purchases with Visa credit cards.
So basically Visa offered Costco a discount if it allowed their cards exclusively. The thing with credit cards is that you can have more than one. I have a Visa and a Mastercard and when I shop at Costco I use Visa. I don't see this reason stopping someone wanting to compete as though if they can't get the Costco dollars, they have no product.
That's not to say that Visa doesn't use lobbying and legal system to erect barriers to entry. But that really has to do with ridiculous regulations and things like KYC, but we're not ready to have that conversation yet.