It seems to me that there is no vision or will from successive Labor/Liberal govts to create new cities to reduce rental/housing pressure and congestion in big cities.
There are so many potential sites to create new SEZ (special economic zones) with existing ports infrastructure, if govt offers incentives, special tax benefits and preferential treatment for foreign investment. Similar initiatives have been successful overseas boosting GDP and economy of the country overall, Dubai, Shenzhen & Johor Baru being the most successful examples.
Also, make it a condition on new migrant visas to live & work in these new cities/SEZs for at least 5 years before granting permanent residency. It will definitely reduce rental/housing pressure on big cities. Australia already has a similar Visa (subclass 491) under which prospective migrant has to work/live in a regional area for 3 years before being eligible for permanent residency and move.
I will probably be the first one to move out of big cities to avail cheaper land, open spaces, better infrastructure, if there are jobs.
Below is a list of locations with existing sea ports in Australia some of which can be established as SEZs and developed further for global trade and connectivity.
This is a great way of stating my view. Half-arsed, dollars-only SEZ style programs are worthless boondoggles.
Comprehensive, long term, generational, nation building projects can work, but have no pay off for decades.