> if your card cannot be processed for whatever obscure reason That's why I carry at least two (physically _and_ in Apple wallet). One Visa, one Mastercard, on

> if your card cannot be processed for whatever obscure reason That's why I carry at least two (physically _and_ in Apple wallet). One Visa, one Mastercard, one is issued by my credit union, the other by a large bank. If both Visa and Mastercard are down and both banks are unreachable then there are bigger issues. Connectivity issues where more common when transactions relied on landlines. It's pretty rare now. I also carry some cash as last ditch backup. Some places may be temporarily not accepting cards.