Our density isn't that low in our major cities - Sydney, Melbourne, Brisbane. Of course it’s super low when we look at the entire (mostly desert) continent.Australia has one of the lowest population densities in the world and no land borders. This has been a huge, huge advantage, more than any government policy.
Agree about land borders. But my point was our states have blocked interstate travel at their borders. I have no idea how easy it is to cross borders in Europe under the current situation?