Thankfully we have great consumer laws in Australia. This is referred to as drip pricing. It also makes practices such as mandatory minimum tips illegal, which would make someone from the US’s head spin.
The only case I can think of where there is a mandatory minimum tip in the US is that a lot of restaurants will charge a minimum gratuity for parties larger than 6-8.
To put it explicitly: if you don't tip, you're personally choosing for that person to make as little as $2.13 an hour for that transaction. Most would balk at pulling that lever.
Well, you are actually pushing their wage downward, but not to $2.13. The lowest would be the minimum wage of the area since the company is required by law to make up the difference.