There is a duopoly in payment processing because it's the most regulated industry in the world. Google, Apple and Amazon are in vastly different businesses, rose to where they were based on the free market and are sustained by it, would be there with or without regulation, and will eventually be replaced.

Personally I don't really care about either of these scenarios and a whole lot of the people complaining about this one are doing it for pretty obvious self-interested reasons, but you're being disingenuous by acting like these are the same thing. Visa and Mastercard are a government-enforced duopoly (with a few minor similarly-enforced exceptions). No tech company is as meaningfully.