Private debt bubbles historically have always resulted in financial crises and major asset price crashes. That is why this issue is very important. In this Youtube clip "Can Australia avoid a financial crisis?" 24/July/2017, Professor Steve Keen explains the relationship between private debt bubbles and crisis. https://www.youtube.com/watch?v=vCFubyGd_R0&t=516s
Steve's line of argument is very much along the same line of thinking of the Austrian School of Economics as it relates to debt.
This chart below shows a longer-term view of Australian private debt to complete the picture.