The SWR is based off the trinity study and basically US stocks. If you were invested in your country and stocks performed differently the 4% rule would also probably not be the 4% rule.
The focus on US stocks makes the trinity study overstate the SWR in general, because the US happens to be one the most successful stock market partly due to historical accidents which are unlikely to be repeated. In the considered timeframe, the US arose from a developing country to the world's leading superpower.
Reversion to the mean implies that investment returns, even in the US, will be lower in the future than during that particular time period in that particular country. Indeed, when historical returns for different countries are considered to account for a broader spectrum of possible events which never occured in the US, the SWR generally turns out to be lower (though not too dramatically for a globally diversified investor).
However, I disagree with the notion that the SWR depends on the country (apart from taxes which I prefer to count as expenses). The events that lower the historical SWR in other countries could also happen in the US and Australia, and vice versa. In that sense, taking into account all countries' historical returns is likely to give a more reliable estimate of the true SWR everywhere, which is probably lower than 4%.
On top of that the Australian stock market has grown over time even with such high dividend payouts.
For limited amounts of time, the stock market is of course expected to grow much faster than 5-7% per year. The 4% SWR includes occasional crashes and crises during which over 50% of stock market value can evaporate very quickly. The main reason why the SWR is still 4% per year is because in a typical non-crash year, stocks grow much more than 4%.
However, when you include major recessions and crashes, taking out more than 4% as dividends is not safe any more, because you need to reinvest part of that dividend during good times to build buffers for the rare, twice-in-a-century events that can destroy a large part of your investments.