Another Australian currently in North America here (though I still do business in Australia). Low-to-midrange talent is more expensive (developers start with a higher salary in Aus); though there's likely more "top end" stuff in the US/Canada (What's the average SF developer salary these days?)

Median salaries are higher, but the standard deviation is lower. Part of this is because the effective minimum wage in Australia is $17/hr. (Benefits are likely more expensive in Aus than the US/Canada as well, particularly if you want to differentiate on giving above average holiday leave etc).

I believe that the article misrepresents facts to make a point that may or may not be there - the type of talent that you'd ideally want to attract (especially as an early-mid stage startup) is likely pretty close in cost to the same talent outside Australia. I'd think that there are more pressing issues (such as the tolerance/approach to failure, or differences in interest rates, which lead incubators to asking for much more equity for less money)...