PPP doesn't matter when you are comparing countries on the global scale.
What DOES matter is governmental revenue.
Australia's Revenue: $473,200 Million
Indonesia's Revenue: $134,200 Million.
Indonesia is not going to be coming anywhere near us economically for a long, long time, if ever.
Indonesia government revenue with rise quicker than that of Australia due to 3 factors:
1. Expected 6% GDP per annum growth versus 3% for Australia.
2. Indonesian government spending is only around 18% of it's GDP versus 35% for Australia. Expect this to rise to around 25% by 2030 for Indonesia while it is likely to say the same for Australia.
3. Indonesia currency is expected to appreciate against the Australian dollar over time.
Sometime in the 2020s Indonesia will spend more in dollar terms than Australia and the gap will then keep increasing.
No way that Australia will ever be able to match Indonesia in the long run.