There are cultural issues at play there which will take quite some time to overcome. High rises in Sydney are popping up around train stations now, but the vast majority of the metropolitan region's land area is taken up by single or double-storey family homes with yards. Pretty much every new high-rise development in these sorts of areas is met with substantial resistance. I don't blame them either - after living in medium-density places in Europe for a few years, I'm sick of it, and want my own house.
The problem with Australia is that too little thought was given to making viable cities outside of the state capitals. I would love to live in a smaller town but my partner needs a major STEM research university to work at. Europe has such universities in small towns, but Australia does not. Everything is too concentrated in the capitals.