Oshkosh is directed at GA. Avalon is not. A comparison is like comparing apples and oranges.
Oshkosh is NOT directed at GA, It's run by the Experimental Aircraft Association, the focus is on experimental aircraft. That doesn't stop GA, the military, airlines, warbirds or anybody else rocking up. The show handles heavy aircraft, mediums whatever. It doesn't shut the airport down and create an exclusion zone around an RPT arrival.
You can directly compare any airshow on the face of the planet. Australia seems to think itself very special on the aviation front. The backslapping is embarrassing.