Systems that rely on the presence of good people to function effectively will always fail. Eventually, with mathematical certainty, some duds will come along. They may not be malicious or outright corrupt, but merely mediocre, narrow-minded, thick will do. And they'll coincide with a period when the system is under pressure.
Duds when things are fine lead to missed opportunities, not damage. Pressure when good people are in charge can be managed. But when both coincide, you get trouble.
Australian politics has been under considerable pressure for some time, and 2019 showed that the duds are in charge. One of the last images of the political year was the most appropriate: Michael McCormack, acting prime minister in the absence of Scott Morrison, railing at climate protesters yesterday as Australia burned amid record heat. No wonder Morrison scurried back early from his holiday.