This seems quite absolutist; why the all or nothing binary of "any case"?
There is merit for harsh policies, to a degree, if you can reduce fallout, to any relatively significant degree.
This may be subjective, but fwiw if Australia were actually monitoring the population via app, requiring check-in every 15 mins & deploying authorities otherwise (a conclusion some commenting here did seem to jump to at first, despite the otherworldly logistics that would entail), then of course questions would need to be asked about authoritarian escalation.
But enforced mandatory quarantine explicitly for those choosing to travel (something that's even been done in some European countries too), given the stakes at hand, really doesn't seem like an overstep relatively speaking.
It's also worth noting that travel in Australia is extremely restricted anyway, so the number of people who are subject to this is pretty tiny.
Note that the South Australia app under discussion is in an Australian state which, like NZ, is relatively successful at preventing “any case”. It seems like the last case necessitating a 7-day lockdown in SA was almost 2 months ago and before then they hadn’t instituted a lockdown since Nov 2020. https://en.wikipedia.org/wiki/COVID-19_pandemic_in_South_Aus...
There is merit for harsh policies if you can prevent any case, what NZ did relatively successfully. But admitting that it failed is hard to convey politically.