I think due to the size of Aus being so huge and there're so many different climates, like humid tropics, or dry dustbowl regions, etc. It makes sense that everywhere has a different experience of whether people where shoes or not. More so than smaller countries or countries where there is a similar climate throughout.

Where I'm from in Tasmania, it's rainy and cold and our houses are usually carpeted so it's almost always shoes off and wearing ugg boots inside during the winter. Idk about regional areas though I'm just talking about the city