Carriers a floating targets with the likes of DF-21 ballistic missiles and there evolutions.
Australia dont need a carrier because you need 3 to be in service so 1 is ready for operations so the cost is a bit steep unless you want some half assed attempt carrier like a LHD.

We nee subs,fighters,ucavs and long range antiship/land attack cruise missiles.

Also instead of naval fixed wing aviation how about intercontinental ranging UCAVS.

I believe Australia gonna bring smaller size again in first size from first 47135 and 200 marines killed in Afghanistan and then theres general staff give up smaller troops and goes up to 58000 but this was only one year old. Over 1500 soldiers of Autralian Army killed outside country and now I hopes Australia goes down to 46330 of theres first size. Kings of Air Force or Naval I belief.