Everyone in Australia just uses paypass/paywave contactless payment with their credit cards. I rarely carry any signifiant amount of crash for that reason. It's essentially the same as using your phone except you use your credit card and doesn't require a PIN or anything for <$100. Once I have a transaction over $100 I can tap and enter my pin, or use chip and PIN, or if everything fails occasionally I need to swipe and PIN. Most critically, signature is no longer allowed.

Without having used WeChat's approach with QR code scanning, it doesn't seem that different for the end user in practice. Either way, you're scanning an object you carry against some target environment and a merchant is processing the transaction for you. It's even closer once you use eg: Apple Pay with your CCs loaded into the Apple system - you're tapping your phone rather than scanning via the camera.

I'm guessing that the CC infrastructure simply wasn't there and pushing out EFTPOS units was a far higher barrier to entry than simply running an app on your newly acquired cheap chinese smartphone. As such, the CC merchants missed the boat whereas the big phone app companies got in on the ground floor. On the flipside, many Western countries had all the EFTPOS terminals already, so contactless just became the next iteration on that.

I don't really necessarily agree with the problem of the country building their commerce systems around Tencent, etc. as 'private companies' since most of the west hinges on Visa, Mastercard and to a lesser extent Amex. They're all private companies too. Maybe the government will step in and standardise the QR code system eventually to reduce the risk. I don't really see it playing out much differently to how the West did with CC contactless.