Why most of Australia is uninhabitable?

Australia is Mars on Earth, very wide, but the only difference is that our Oceania country is slightly habitable. Australia is the sixth largest country in the world, with an approximate area of 7.69 million square kilometers, falling behind Russia, Canada, China, the US, and Brazil. Even with this huge area, Australia has a modest population of 27.6 million as per the June 2025 data from the Australian Bureau of Statistics. This makes it one of the least densely populated countries globally, with an average of 3.5 people per square kilometer, causing a mismatch between its geographical vastness and human habitation. A key factor behind this low population is the harsh environmental conditions of Australia. Outback or Vast swathes are the parts of Australia that have arid deserts with very high temperatures, water scarcity, and poor soil quality, making these areas mostly uninhabitable for mass settlement. Ecological studies that examine the correlation between human population density and biodiversity show that extreme environmental conditions push large clusters of population to reside near coastal areas. Therefore, more than 90% of Australians reside within 50 kilometers of the coastline, mostly living in urban centers along the eastern and southeastern seaboard.   This is…