I'm not sure of the minimum wage in either the States or Oz at the moment. But I'd say, in Oz it is probably between 2 & 3 times that of the States. Tipping should not be necessary.
Our forebears fought long & hard for a living wage. Everything from court action to pitched battles in the street. I don't like anything that puts that at risk. We got rid of the last government for trying to take the outcome of those battles away & turn us into Americans with their hand out for a tip just to survive. Well there may have been a couple of other reasons too, but that was a big one.
No one in Oz has to work for peanuts. So if they do, that's their choice & they can live with their own decisions. In Oz, people get paid a proper wage to do a proper job. There should never be any need tip someone. If they want more money to do their job they can talk to their employer, who has already folded the cost of a decent wage into the cost of the good's or service supplied.
I won't tip, I'v knocked back more tips than you can pock a stick at. The only place I'v ever dived where they pointed out the tip box (Queensland) I laughed at them & said if they want their employees to be paid they can charge enough up front to support the wages.
In short, I HATE TIPPING.