Many homes are now vacant and have become owners holiday homes due to the Government forcing restrictions on Landlords. he proOne of my rental properties I've taken off the market permanently, dealing with some tenants is painful so better keep the place vacant and use the property occasionally myself when I want to visit the big smoke for a few days. These days tenants have more rights than the owner.
Many foreign owners are doing the same, they might use the property once or twice a year when they visit Australia and in some cases allow their family or friends to stay.
Australia allows foreign ownership, try buying a block of land in China, Thailand, Laos or Cambodia. You need to jump through a lot of hooks, most illegal.