The one thing I like about the credit card system (as opposed to "app" pay system) is that the usability is so much better. You don't have to worry about your phone being smashed or running out of battery. It's also less work than a phone, all you need to do is wave your card in front of a reader. No need to get out your phone, unlock it, open the app, wave around your camera so it scans, and finally confirming the payment. Not having to install a potentially privacy invading app is also a plus.

Wouldn't work in a lot of places where there's no LTE reception, though that will probably change with things like 5G and Starlink.

I also wouldn't want my ability to pay to be tied to my phone. Not only do I want to be able to pay for things even when my phone is dead, but it just seems like it would add yet another vector of attack to steal my money.

> > Another method would be a standardised QR code so that you can make a transaction from your app by scanning the qr code.

> Wouldn't work in a lot of places where there's no LTE reception,

I happened to read about this recently (https://www.emvco.com/emv-technologies/qrcodes/), since it's going to be the base of Brazil's new instant payment system to be released later this year (PIX - https://www.bcb.gov.br/estabilidadefinanceira/forumpagamento...).

From what I understood, it does have a way to do offline transactions. There are two kinds of QR codes: one which is scanned by the app and used for both online and offline transactions, and a second kind used when offline which is presented by the app and scanned by the POS. This second QR code contains data similar to what a chip card would return to the reader during an offline transaction, so the transaction flow after that point is similar.