Such robustness is currently a subject of government studies and planning. It's definitely an area of concern.
A personal-level outage is a problem but less so than with cash. I have three separate items on me I can use to pay - my card holder with bank cards, my phone and my watch. That's more redundancy than with cash, which is one item (wallet).
Power or network outages aren't a big issue. I've experienced those and it's smooth. Most payment machines work fine without power (batteries) or without network because they then store the transactions locally and send them later. I've even had lunch when the lunch restaurant was having IT problems and couldn't accept any payments - they noted how many people came on paper and I came back the next day to pay, as I'm sure the vast majority of patrons did.
Bank or card issuer outages are handled by using another card or payment method. If some bank's cards aren't working (uncommon but it happens), mobile payments generally work still, and most people have more than one card.
Major national level outages are a concern. It would be impossible to buy e.g. a train ticket as those require immediate payment, so if somehow Internet was down nationwide, you couldn't get a train ticket online or at the ticket machines. This is one major goal that the e-krona (state-issued digital currency) project is meant to address as e-krona is intended to also work offline.
A personal-level outage is a problem but less so than with cash. I have three separate items on me I can use to pay - my card holder with bank cards, my phone and my watch. That's more redundancy than with cash, which is one item (wallet).
Power or network outages aren't a big issue. I've experienced those and it's smooth. Most payment machines work fine without power (batteries) or without network because they then store the transactions locally and send them later. I've even had lunch when the lunch restaurant was having IT problems and couldn't accept any payments - they noted how many people came on paper and I came back the next day to pay, as I'm sure the vast majority of patrons did.
Bank or card issuer outages are handled by using another card or payment method. If some bank's cards aren't working (uncommon but it happens), mobile payments generally work still, and most people have more than one card.
Major national level outages are a concern. It would be impossible to buy e.g. a train ticket as those require immediate payment, so if somehow Internet was down nationwide, you couldn't get a train ticket online or at the ticket machines. This is one major goal that the e-krona (state-issued digital currency) project is meant to address as e-krona is intended to also work offline.