What factors led to the effectiveness of the Melbourne lockdown? Choices are things like compliance, geography, particulars of the rules (8pm curfew, 5km movement radius), enough of a population that is able to work from home, enough economic support for those who couldn’t (job keeper etc) - to slow down population mixing and interrupt transmission chains. Contact tracing was overhauled midway through and that coincides with the turnaround [0,1].
Would those measures work in similarly-high-density cities? The awkward fact is that most of the cases in greater Melbourne were outside the densely-populated CBD [2], that much of the transmission occurred in lower-paid (McDonalds) and less-safe (meatpacking) workplaces, people whose home language was not English, as well as in shared living conditions.
There’s a temptation to fit the data to the narrative you want, but (as far as I’m aware) the data you’d need to pick any one of these factors as conclusive hasn’t been released. Gestures in the direction of geography as the _one thing_ that enabled elimination are silly and ignore the vast amount of effort and personal sacrifice and organisation and argument and collaboration that went into that result.
Lockdowns do work — even if that’s not quite the end of the story.
[0] https://theconversation.com/where-did-victoria-go-so-wrong-w...
[1] https://www.abc.net.au/news/2020-12-14/victoria-coronavirus-...
[2] https://www.dhhs.vic.gov.au/sites/default/files/documents/20...