Why is the current government who must support these policies still in power?
Politics is almost as complicated as climate change. It's basically the Labour party (roughly equivalent to the Democrats in the US) who are fighting for a reduction in CO2 emissions. The Liberals, who are currently in power in the Australian Federation (roughly equivalent to the Republicans in the US), have a more practical view on energy supply, and would like to extend the life of current coal plants, and/or build new plants of the latest Ultra-supercritical variety.
Unfortunately, the current Liberal government does not have an outright majority in the Senate, so has great difficulty in getting new legislation passed. Individual states also have the power to make their own decisions.
Because the future of political decisions, depending on which party is in power, is very uncertain, private companies are reluctant to invest in new coal-powered electricity plants, even though the latest technology can guarantee that emissions which are harmful to health are reduced to negligible levels.
The state of South Australia, under mostly Labour state governments, has made a transition to renewables, and has got itself into trouble, due to the unreliability of renewables, which is why it has now commissioned the building of the largest battery storage system in the world, the current Tesla project.
Australia in general is high on the list of energy costs, but South Australia is the highest. It'll be interesting to see if the Tesla battery project brings the costs down.