It worked particularly well in Victoria, where a second lockdown turned a ~700 case per day nightmare into 38 straight days of no deaths or locally acquired cases.
The lockdowns were terrible for many people - for all the reasons you can imagine. On the other hand, I doubt anyone here would now argue that those crazy times were a mistake.
I think it's fairly clear that lockdowns that actually lock people down are undeniably effective. The question is really whether or not imposing a lockdown in any given population will actually result in people cooperating, which I think is debatable for a lot of parts of the US, where we are taught to take a lot of pride in our inability to be controlled. I think the acknowledgement that a lockdown doesn't necessarily have the effect you think it will is a recognition of that cultural phenomenon.