IMO, you have fallen for a rookie investor's error by only considering price data since the 90s.This error is called 'recency bias' - and you can read more about it on Investopedia HERE (it is number 8 on that list).
Clarke McEwan are accountants/business advisors so they will be acutely aware that a lot of things can affect house prices and ALL markets move in business cycles. What makes the Clarke McEwan analysis so insightful is that it considers house price movements since the beginning of Australian Federation.
Over this longer time period, you can see what effect periods of deflation, wars, pandemics, credit booms etc all have on house prices.
In contrast, a house price analysis done over only 25 years can't possibly claim to know everything about the Australian housing market.
