The whole point of the lockups was/is to allow frontline and other healthcare workers to prepare and sustain their ICU capacity. To ready themselves for the onslaught and then be able to keep up with ongoing new cases.
I think that is a point that many miss.
Overwhelmed ICU and hospital facilities = no prompt or proper medical assistance for many people. Not just covid cases, but for people having heart attacks/strokes/serious accidents ......
Well, the other goal is to get case loads as low as possible - as your nation has done. Then, suppress new outbreaks with ease, given that time was bought, new information is available and there are hardly any cases.
The number of cases needs to be very very low before "reopening." You guys did that, we didn't do that.
We are now having the problem you mention (overloaded hospital facilities, cancellation or transfer of regular patients, etc) in some states, anyway. And the only way to get out of it seems to be to shut down (as Florida and Texas are now doing a second time).
It helps that your population is a bit more spread out - but that's true of some places here too. Your population is almost the same as Florida's. Yesterday, Australia had 27 new cases for the whole nation. Florida had about 9000.
Yesterday, Australia had 1 death. Florida had 37 and is projected to go much higher in about a month, as the large number of new cases moves through, hospitals are crowded, medical staff are stretched - and new patients continue to increase in number, must be tested, triaged and treated. We're sending a lot of people home to self-isolate (with symptoms). In Florida, many of those people are young and live with extended family or with friends.
Texas is a bit larger than Australia in population. ~5100 cases yesterday and 32 deaths. It's taken a while for CoVid to really root itself in Texas - it could have been prevented, I suppose.
But we'd all have to work together like Australians, Canadians, Greeks, Vietnamese and New Zealanders did. Or at least be compliant and rigid about rational rules imposed by governments, as some nations did.