That is just taking one stat and using it as a deciding point. Auckland has the major NZ cities and Melbourne a similar distance to Sydney away. Honolulu has the 2 other main islands (pop 100K + cities) and then its Southern California as far away as Adelaide is from here.
There are no other cities at all close to Perth. Nothing. Bunbury at 70K is the only population centre of note. Then its is Adelaide. And nothing.
There would be less population within 3 hrs flying time from Perth than any other city in the world.
Honolulu to LA is nearly double the distance perth to Adelaide.









