> The US government will never be permitted
Then why don't corporations regulate the government, instead of it being the other way around? Why did the minimum corporate tax rate just go up to 15%? Why is there any corporate tax at all? The US government pushes companies around anytime they see fit. They're a superpower with the world's most powerful military, the FBI, CIA, NSA, and dozens of prominent regulatory agencies that control every aspect of the US economy.
When they decided to go after Google, guess what happened? The founders of Google immediately ran away in fear. They promptly resigned simultaneously and shrank from view. They knew what would happen and they got out in front of it.
When they went after Microsoft, guess what happened? Bill Gates resigned from leading the company that he founded and had been in charge of for a quarter century. The most powerful, richest private citizen in the US gave up control over one of the world's most powerful corporations.
The feds are drastically more powerful than any private citizens or corporations. Corporations are run by people, and people are very easy to target and easy to break, especially when you have powers of an epic scale central government.
Even a company the size of Apple is barely a spec to the US Government (a government which is currently engaged with Ukraine in smashing the supposed #2 military, Russia, using just a modest flex of its weapons and capabilities). Only China's government comes close to rivaling the US Government for power, corporations are a joke by comparison.
If the feds want to implement an instant payment system, then that's exactly what they'll do, whether Visa or PayPal likes it or not.