VFR aircraft position reports - VFR have responsibility to see and avoid

When flying through the radar airspace within 45 miles of Sydney there is an almost constant barrage of VFR aircraft with verbal diarrhoea. Despite this, 80% of the aircraft I see have not made a radio call.

Does anyone know an advantage of 20% of the aircraft making position reports and 80% of aircraft not doing so? Should all of the aircraft make reports? This would, of course, lead to “wall to wall” talking.

How does see and avoid work?
All VFR aircraft (and IFR aircraft in VMC) have a responsibility to see and avoid. The problem with only a few aircraft making position reports is that other pilots tend to concentrate their look out in the direction of the reporting aircraft and neglect to scan for non-reporting traffic.

Remember too that unnecessary calls on the frequency can block out more important transmissions – possibly even emergency calls.