I'd argue that their weakness is governments more than companies. Governments are eventually going to see "a foreign company owning our major payment networks"

I'd argue that their weakness is governments more than companies. Governments are eventually going to see "a foreign company owning our major payment networks" as a national security and sovereignity risk, especially if we end up in a multi-major-power world. They'll also eventually covet the data and the ability to disable "inconvenient" business. You might see it take the form of a government-mandated account (would Visa/Mastercard have taken off at the same angle if universal, instant direct debits were available in the US?), or just providing a glidepath for local commercial alternatives. Look at what Russia is doing with the Mir card.