How do you define "power" exactly? Like the Supreme Court just flipping constitutional law precedent? Or that the government isn't being held to account in front of an independent judiciary?
Because we see that reasonably often in NZ, government gets taken to the High Court, loses, formally apologises, tries to get it right. If that's missing in Australia, that really explains a lot of us on the other side of the ditch have seen the federal government getting up to.
Of course we don't have any federal bill of rights in Australia, and the implied rights in the constitution to thing like political speech can be violated so long as the court thinks the government had a legitimate reason for doing so.
You can complain about parliamentary sovereignty all you like (for us it’s only the states that have plenary legislative power though!) but damn, at least the people deciding about abortion rights etc on our behalf aren’t life appointments set to last 30+ years. If we don’t like what’s happening, we can change the government in 6 weeks start to finish.
In order for American constitutional law to make sense again, they should either strip the entire bill of rights from the constitution (slowly!) or once again do a huge U-turn on Dobbs (and the cases yet to be handed down in which the conservative majority will use the same ridiculous legal test that is even less rooted in the text of the constitution than the rights they're analysing to justify knocking down the right to gay marriage etc) and acknowledge it was bullshit. My thought at the moment is that doing it Australian-style is better in the long run. You get slower progress, for example we had discriminatory laws against sodomy in Queensland until 2016 (!), whereas the US has benefited economically and socially from the extremely sound policy of abortion access (cutting off a poverty/crime pipeline) for 50 years. But you don't get the instability that results from populist movements cottoning on that an independent judiciary sits in their way. As it stands the US is there. It's a very dark spot.
I have read both the judgement re: WA which upheld the State's Right to enact quarantine during a biosecurity emergancy "while that situation lasted" and I've read the Australian Constitution, in particular the passage that supposedly allows free unencumbered travel between States even during a pandemic (which, I'm afraid, it doesn't).
These specifics aside, I agree that various Federal Governments have pushed past the bounds of what most citizens find acceptable and it's right and correct that they push back and mount challenges.
In the specific case of these environmental protestors I feel the former Government did go to excess in surveillance and stalking them in a manner befitting terrorists plotting malfeasance. No soup for them.
In the same manner of fair view to both sides, this particular protest group had in the past and did intend in the future to go beyond public and visible protest and fully into the realm of trespass and disruption of ongoing business activity.
Personally I applaud the ascent and hanging from a coal port stack loader - it was a ballsy move and good publicity and reminds me of things I did on several occassions in my 20s - but it was also trespass and beyond mere protest.
None of which justifies the excess bail conditions outlined in the OP article.
Obviously the judiciary is much less powerful here than the US, but my point was how power has been stripped away from party members, legislatures, the civil service, and most of the political executive. Even senior ministers have effectively no political power whatsoever, they're just sent out with their lines to read. All the power is concentrated within the PMO (or Number 10 in UK parlance), which nowadays solely dictates party strategy and policy.
As for the WA border closure, if you read the judgement it did not say that the constitution only applies to the trade of goods. In Australia constitutional rights can simply be overridden by necessity. You saw the same with the implied right to political communication which has been routinely ignored, as in the Bolt case. If you want to read up on this, look up the doctrine of structured proportionality especially as it's been applied since McCloy. Basically governments can flagrantly breach the constitution and then it's up to the courts to decide whether the transgression was justified based off their own value-judgements. The court was satisfied there was a public health justification for the closure, so s92 goes into the bin.
Realistically until Kiefel and Keane retire, Australians don't have any genuine constitutional rights because they'll just extend the doctrine of structured proportionality to whatever constitutional right is in question. "Non-absolute" rights are simply not rights in any sense of the word.