Yes, but Australian, (and Canadian, and New Zealand) cities are all in the same range as many similarly sized American cities. Maybe Auckland has transit as good as Seattle with half the population, but it's not the order of magnitude difference that US vs European or US vs Asian cities do. All of the Anglo settler-colonies have rather lackluster transit compared to the Old World, and one of the first things I tell anybody who wants to come to New Zealand is to plan on having a car.
I jest, but not completely. The US is more dense but more distributed too. You can’t realistically link someone in a rural West Virginia holler up to a regular bus schedule, nor can you build a train between Morgantown and Pittsburgh that gets ridership.
America doesn’t do badly at public transit in places like Florida where private companies can fill the gap and the communities are within a reasonable distance and the geography is flat and simple. See the Brightline trains for proof of concept. But it’s kind of ridiculous to imagine Australia and the US to be comparable in that way.