This is a bit time-frame dependent. Australia was the richest country in the world a century ago, so in that context they haven't done all that great.
Of course Australia is no longer the most favourably positioned part of the largest commercial Empire on the planet, but, yeah, fair point. I think the main thing to note about Australia is consistency; it has pretty always been an extremely prosperous place for ordinary people, at least compared to elsewhere. It's why they found it so easy to boost their population through immigration post-war, and so on.
