Those alternatives are not worldwide payment networks with near-universal acceptance. They’re scoped much smaller. Even then, those independent efforts have either been implemented by law as a political strategic measure or are subsidized. They wouldn’t exist but for those supporting elements. Having federated payment networks may be good politics, but it’s not particularly efficient and it impedes world trade.

At any rate, making someone who haughtily trivializes a problem solve that same problem is a useful exercise both in the complexity of the subject matter, and—perhaps more importantly—in humility.