Being Australian, I imagine it's because everything is so spread out with a lack of infrastructure to boot.
Massive inefficiencies across the board with high costs associated with things which would improve this metric. Its extremely difficult to reduce your impact here without significant cost, and that cost is out of reach of the typical Australian. Things that do have impact (solar/batteries/water systems/electric vehicles) are excessively expensive compared to the alternatives, and the median Australian wage is around 65k.
As an example I just had a battery priced for my house, government subsidy included is $25k. Its not practical for most people.
Android auto is working, has been for a while. Its in the Graphene app store.
Major issues are typically banking apps, though I've been lucky in that regard.