Hmm, that's surprising. I have traveled a lot in Asia (never to Australia though) and from that experience I know a lot of Asia is still cash based but Australia I'd expect every coffee / convenience shop to accept Visa/Mastercard.
That is fascinating. As someone who lives in Sydney's outer suburbs, I simply never need cash. For anything. It's almost the exact opposite of Germany, where I lived for most of the last 5 years.
For sure many coffee shops and convenience stores accept card, but I definitely find myself having to pay cash quite often (just for instance, the laksa place on Hunter street).