You seem to be laboring under the misconception that people don't want to pay for things by card.

Card payments are more convenient than cash.

They rely on a network, which costs money. Yes, the fees exceed the cost, which allows the network provider to make a profit. However, if the profit was excessive there would be alternatives, and most Australian's will be invested in that payment network through their super anyway.

In summary, consumers are enjoying convenience in exchange for a fee. You personally might find the fee unreasonable but you're the minority.

You seem fixated on the idea that when paying with cash you will be burdened with the card fee even though you're not availing yourself of that service. I'm a self employed consultant. The vast majority of customers pay electronically, by bank transfer. A few times a year someone wants to pay with cash, so I have to make a special trip to the ATM to deposit it just for them. Handling cash has a non-trivial cost.