In the UK and Australia where I normally am, card infrastructure is just so entirely universal and reliable that it's not even worth considering.
Now days they can print you a new card in real time at the branch, but still I will never not have cash, and not have a backup card
I also NEVER use by debit card for anything other than ATM now, credit cards and pay it off every month... I dont even carry my debit card anymore, it is locked in the safe, and a bring it out when I need to get more cash.
I don’t have a wallet, and I don’t want one. I want efficient and secure digital currency, with easy interfaces between digital wallets. I pay for my lawn care via Cash App, most of the other small businesses have Square or something similar.
If I need anonymous currency, I will convert to crypto and then convert once or twice more across different coins. It’s good enough for my use.
Those problems do exist, I usually just go somewhere else if their card/payment reader is down.