Look, I can't speak for Australia. I just know Midnight Oil, and they had plenty of beef with Australia's government.
But the US can hardly even keep track of who has been vaccinated and who hasn't, who has had covid and who has not, who has died from covid, who has not. We are not on the cusp of some covid surveillance state. And requiring vaccination, even among those who have had the disease, is a defensible policy, not least because the extent of immunity to the virus depends on a number of factors (like how sick you got, how old you are, how long it has been since).
In my experience, most arguments about slippery-slopes to hell are just wrong. Probably because the slopes aren't that slippery, or the slope is so shallow you don't really know which way is down, or because predicting the future is actually really really hard.
It's the frog in the pot. We have never had the capabilities for mass surveillance and complete control over who participates in society, to the extent that we do now because of technology. Stalin would be salivating if he was still alive right now.
The data is on my side. The pandemic, while very serious, has touched over 100 million Americans directly (in the form of past covid) and I would still bet that the majority of those people would recoil in horror at what's going on in Australia or move away from NYC's "papers please" model if they had a choice.