> No, these companies keep themselves in power not because they've solved such a difficult problem that nobody else can, but because they have a moat which they protect.

I don't know that the problem is sophisticated, but it's certainly complex [1]. It's a bit of both in terms of complexity and defending a moat, which all businesses do, including, and especially European ones.

And companies like Visa, Mastercard, American Express, &c. arose initially from solving a real need. Before these companies came into existence when you traveled you'd have to take cash, or traveler's checks or some other nonsense. Today you can, at least as an American, just walk in to the subway in just about any country and tap to pay. Need a coffee at Mt. Fuji? Easy. Buying a bottle of Calvados in some remote area? Yea just tap to pay with your Mastercard.

> Time to do away with these foreign entities.

You'll never do that. Why? Because at a minimum you want American tourist dollars and Europe isn't going to start issuing European credit cards to Americans or other citizens around the world.

[1] Why is it complex? Well you have to deal with American and European financial regulations, KYC, &c. - you have to vet merchants, you have to run the infrastructure to process transactions, refunds, direct payments from bank accounts to pay for cards, and all of those things. Those are real, genuine business activities that are non-negotiable and while they may seem simple, in practice they are not at all simple.