Answer: if Charles is unable to perform his duties as Australian head-of-state, the Australian Governor-General is left with even greater power - for an indefinite time! Not a good look, given the performance of some of our previous GGs.
Look, I get that many Australians - me included - have some lingering nostalgic thoughts about the British monarchy. But entanglement with the Brits is outdated, unnecessary and frankly a little embarrassing. We can - and should - have our own head-of-state, which, despite the whinings of the Monarchists - is not the GG. Yes,
it would mean a new system and yes, that might come with its own ups and downs. But surely we are not so craven as to think we can't come up with a system that suits us, and adds value to our reputation in the world as an independent, creative and strong democracy.