Australia covers an area of 7.692 million square kilometers. Therefore, the annual rainfall exceeds 600 mm, and the rainfall in 20% of the area is twice that of France (considering that most of this area is tropical or subtropical). Most importantly, the population of Australia is 25 million, while the population of France is 67 million, so the cultivated land in France is only half that of Australia, and the rainfall is only a quarter of that of France, but it supports 2.5 times the population of Australia. Australia is not short of water, but it is incompetent and stupid.
The main reason for the development of Australian cities and the disappearance of inland towns is that Australia has always been a net exporter of major resources. We export minerals, cereals, livestock and other agricultural products, coal, natural gas, oil and infant formula. In the 20th century, the decisive feature of primary resources is that they become capital-intensive rather than labor-intensive, so the demand for labor (people) to produce primary resources is decreasing throughout the 20th century. In net exporting countries, economic activities are developed around shipping ports. International trade needs banking services, capital markets, futures markets, insurance, sales and marketing, and legal services. Service industry is traditionally a labor-intensive industry, so managing the export of these resources requires more people than producing them. They also tend to get more pay.
Of course, all people engaged in the service industry need to eat, dress and have fun. This is the main reason. Other reasons include: Australia's coal resources are mainly distributed in the Great Watershed area, which is on or near the east coast. For example, in Wollongong and Newcastle, coal is just below the coastal cliffs, which makes it an ideal place to place heavy industries such as steel manufacturing on the coast.