If 75% fewer households have guns now than before you were disarmed decades ago, then saying Australians were disarmed isn’t a myth, and an increase in some people collecting rifles doesn’t make up for what was and for the likelihood that pistol ownership would have greatly increased during these decades of new immigration and unease.
Here is an explanation of the many rules and hoops to jump through and the limitations while owning, and the expense of it.
https://www.twclawyers.com.au/gun-laws-in-australia/
The 75% figure is not accurate in my view. It comes from one piece of research that has significant flaws. There are other estimates that are quite different.
The article you’ve cited is primarily about gun laws in one state, and seems to be just assuming that those laws apply across the country. That might have been a fair assumption twenty five years ago in the wake of the National Firearms Agreement, but things have changed in a lot of places since then.
I’m actually quite surprised that Queensland may be as restrictive as the article implies. A lot of what is in the article doesn’t match my experience in Victoria - and honestly, I would have assumed we’d be worse than Queensland (we have the most ‘woke’ socialist government in the country).