How does the shitshow end?
The US Empire collapses (ie they no longer have reserve currency status, their military is no longer no. 1, their treasuries go to shit)
Not going to happen.
China invades Australia
Not going to happen (for the cost of invading Australia they could invade a lot of other countries).
International finance cuts off Australia
Not going to happen because our politicians are too politically correct, they never rock the boat and the USA runs international finance anyway and we're part of the in-group (because it suits them).
Boomers die of old age
Will definitely happen in the next 20 years, but that's a long time. Anyway, it really depends on whether or not millennials are able to think for themselves or just become the next boomers. If they do then everything hinges on what happens with the millennials die, in another forty years or so.
Global population peaks so the supply of new immigrants is reduced.
Plausible, but about 70 years away.
For the foreseeable future, everything just gets shitter and shitter.