Much of the world uses mobile payment apps instead of credit or debit cards. Some banks allow a setting that using a card can require a ping to the banking app for verification of the transaction. I don’t know if it’s legal to turn down cash payments in Vietnam, but some vendors may only accept digital payments.

I guess you could take your laptop out at the restaurant and in the taxi to pay. It seems a little strange. You might better just use a browser on the smartphone instead of the mobile app.

I guess I take credit and debit cards for granted. Surely the rest of the world had some solution before smartphones, though. Hopefully the US doesn't descend into needlessly using the phone as a middleman as the norm.

> But I've never used a banking app on my phone before.

Here in Europe, good luck using any form of online payment without one due to 2FA requirements.

I don't have a problem with online payments, and I'm not using a banking app.

> But I've never used a banking app on my phone before. Anything important I still like to do on a desktop.

A lot of banks require using their banking app to get a 2FA token to log-in on a desktop web browser.