While the aboriginals underwent and still endure settler colonialism it hasn't been as long or quite as thorough as the Roman occupation and then christianization that the celts went through. Australia is also so much bigger than the UK, so it would be hard to complete a very effective act of genocide against spiritual or tribal leaders as they did to the druids.

Even so some Celtic oral traditions were still going on strong up till the 19th century, often being little changed over thousands of years.