For once I don't blame Apple
since Australia's government is worse. Australia's daylight saving regime is a bloody joke, and most devices that adjust for daylight saving get it wrong, not just Apple's. With different daylight saving times in each state (which means no less than 6 changes as each state government has its own criteria for setting when it happens, and the fact that the day it happens on changes every other year as one state government or another decides to bring it in early or late to accommodate some event or other - it's no surprise timekeeping devices can't keep up.
I gave up trying to track Australia's daylight saving system in my web app code years ago. Since we're based in Adelaide but our servers are in Sydney, one can imagine the daylight-saving horrors we went through each year, as SA goes forward but NSW does not, and so on. After much hair-tearing on my part, all the timekeeping applications on our websites now go by GMT and I adjust the current time with a constant in my code which I can manually toggle to add one hour or not. And I toggle this constant myself, twice each year, whenever DST happens to fall. It's the only way I can make it work!