Are you forgetting the USN 7th Fleet, plus the 8 carrier groups
The Chicom PLAN fleet going to Australia would be SITTING DUCKS,
but somehow I don't think that even the PLAN is suicidal enough to attempt anything so futile,as an invasion of Australia
There is ANZUS,(US-Australis-New Zealand) the mutual-defense pact of the Anglo-sphere world
An attack on one Anglo, is an attack on all Anglos
Let the Chicoms beware
If it happens tomorrow, you are right. However, don't count it out after a few decades of "uninterrupted" growth. Of course, I even doubt that there would be "uninterrupted" growth. With that and more Chinese on Australia, after reshuffling political alliances, it is possible.