I think the other issue is that "crypto" is not "money". There is no card I can carry that I can take to an ATM and convert crypto to money knowing before I left my house that day exactly how much I would get down to the penny.

Crypto has value the way Gold or pawnable items do, and until that barrier has been crossed the people will never embrace crypto as an alternative to cash and credit.

Realistically the only way for that to happen would be if the US replaced their currency with a government backed crypto, but that is unlikely to happen without a coup.

Visa and MC could still offer lines of credit in such a system but they would not be the primary purveyors of capital motility and therefore their entire business model would collapse or require extensive restructuring.