Exmouth has supermarkets and is supplied ex Perth so all the systems are in place.
Right, so that's it then. The only thing that's required to support a RAAF base is a supermarket. Exmouth has one, so therefore 'all systems are in place'. Dream on...
What about the huge investment in infrastructure that would be required to bring Learmonth up to a suitable standard to support high intensity training operations? At a minimum, that would include new apron areas, hangars & maintenance buildings, taxiways, fuel facilities, ATC facilities (including radar), an ILS for IF training, classroom & briefing facilities, accommodation and mess facilities, operations & admin buildings, air movements facilities to support visiting aircraft, etc, etc...
Not saying it can't be done, but the initial investment and ongoing support costs would make it a VERY expensive exercise. Further, is it a wise move to put a major training facility 'up north' where it would be far more vulnerable in the event of a conflict?