So far as I can tell, the fold card works by selling your bitcoin to a market maker for fiat and transacting that, it let's you spend actual bitcoin too, if the merchant accepts it, but then you wouldn't really need a fold card for that. That must be kyc though, and taxable events, I assume.

What if

That market maker was an agorist exchange, where I can use whatever payment method, a prepaid card or venmo/strike etc. to buy however much bitcoin customers are selling that day. So Alice goes to buy a pizza from bob, alice taps her phone to the payment terminal, and Luke's card gets charged in exchange for the sats. As far as Luke's bank is concerned, he bought a pizza, Alice doesn't need to worry about her bitcoin sale being tracked, and Bob gets his fiat.