Instead of, "Don't leave home without it!", leave home without data on phone. :)
They take a whole dump for future forensic if needed, and that includes the ability to restore what you have deleted.
But I do agree with the grandparent comment that this extreme level of airport search intrusiveness does legitimately make Australia a much less attractive tourist destination. And btw, as an Australian, I feel somewhat the same way towards the USA and its intrusive airport searches (which is what we are slavishly copying).
Not only that, but most of the species are common in the USA and EU and just have different names.
Also, the US has far more dangerous animals, but somehow Australia is famous for that lol.