Basically half of us live in 2 cities as it is and we’re more urbanised than the US, UK, France, or South Korea.
Very few people live in the vast expanses of land, and rural towns are shrinking. We all live in very few cities overall. It’s easy to cater to that if we bothered to.
Nonetheless, even if we conceded that one needs a car to get by in Australia, the cars don’t need to be as large, and with such lethally poor visibility as in the US. While the US is (outside of small pockets) a dog-eat-dog society where you either project dominance or are dominated, Australia still has some semblance of a social fabric, an existent if somewhat threadbare welfare safety net and the fabled ideal of “mateship”, meaning that we don’t need our cars to look preemptively threatening.
Yes, these trucks don't do any job particularly well. They don't have big bed capacity, they have terrible visibility, they're extremely dangerous, and they're not even particularly good offroad because they're not built for that. They're built to exceed certain weight limits in the US's EPA regulations to reduce their cost. There's no point doing that then adding a bunch of expensive suspension components. You're much better off with a 20 year old Hilux in that regard. They only look like utes because you can't sell a 4 tonne family sedan, because people would notice it was useless. The tiny bed in back is a fig leaf.
The vast majority of Australians live in a densely populated strip on the east coast. It should have high speed rail from Melbourne to Brisbane decades ago.