The difficult thing is... when does it stop? The above could have been said 10 years ago, just replace the 3 with a 2. Should it have stopped then? Now? In 10 more years?
It's not fake money. It's likely not even "beyond means". The debts can likely be paid back. But it seems quite unlikely the level of spending can continue to grow.
However Australia has such a large amount of land, and such a small population that forecasted worldwide population drop won't affect Australia so much. It's such a desirable place to live that immigration at the current rates will be sustainable regardless of the rest of the world's population growth rate. Whether or not our cities can keep up with the growth and maintain their high levels of livability is another question.
I'd also question your statement about population drop on the next 15-20 years. All forecasts I have seen are that the world's population will continue to grow until the end of the century. If the world's population were set to start shrinking in such a short timeframe, I'd think it would be a huge talking point in any discussion about sustainability and global warming.
I am always amazed at news reports from Japan about how the sky is falling because their population is shrinking. For some reason no one ever says "on the plus side, Japan is one of the most densely populated places on the planet, a slow decrease in population will help improve quality of life measures and sustainability".
There is still time for a pop once governments decide things are normal again after covid.
While thats true on its face, in practice trying to make that bet is a fools errand at this point. People have been telling me that for a decade plus, now. It still hasn't happened, and the Australian economy (and household wealth) is inextricable intertwined with real estate -- I can't see any government deciding to let it "pop", personally.
They won't let it pop, but that doesn't mean it won't. Of course, timing it is the big bet, not predicting if it will happen.
Australian property prices are cyclic with an upward trend. There are (substantial) cyclic decreases in prices, especially in Sydney[1].
But people who talk about "popping" property prices seem to believe there will be a massive (50%+?) fall in prices.
But there are fundamental reasons why this is unlikely. The 2008 GFC causes a 16% decrease in prices in Australia[2], and it's hard to imagine something being worse. Prices recovered 10% the next year, because Australia avoided a recession and there is fundamental demand for living areas in out major cities.
The GFC caused a 18% decreases in prices in the US[3]. Given that Australian mortgage rules are different (there is no ability to walk way from a mortgage in Australia, unlike the US) it's unlikely a bubble in Australia will "pop" worse than that.
But 10% decreases occur relatively often. For some reason these are ignored, but the truth is these are the "pops" that take the froth out of the market.
[1] https://cdn.propertyupdate.com.au/wp-content/uploads/2021/03...
[2] https://www.theguardian.com/money/2009/jan/06/house-prices-f...
[3] https://money.cnn.com/2008/12/30/real_estate/October_Case_Sh...
There's also reason to believe that the Australian property market has decoupled from the rest of the economy, and that's because tax breaks like negative gearing incentivize buying properties even when it makes no financial sense otherwise. This could change overnight with the stroke of a pen, but it would take an awfully bold politician to do it.