Australia sacrificed international travel too. It still leaked in which led to occasional limited lockdowns. Until Delta strain hit and spread too fast for the small lockdown strategy to contain it.

Australia screwed up the vaccination strategy. They bought AstraZeneca and relied on a domestic vaccine that was being developed which failed in trials.

Then the AZ side effects became an issue and there was no backup plan.

But even the AZ rollout was a debacle with no one sure if they were eligible or how to get it. And the Prime Minster excusing it all by saying "it's not a race".

If Australia had the vaccination rate of the US or the UK (which was absolutely achievable) then Australia would still be the envy of the world.