anywhere else in the developed world IFR aircraft receive an ATC service at all times, with the applicable separation standards. Low level ADSB means ATC can apply better separation standards.
The problem is that without VFR aircraft on ADSB, the separation standards cannot be anything different than they are now.
Australia is the only country in the world that is
MANDATING ADSB for
ALL IFR aircraft in ALL airspace types.