In fairness to those running ‘the system’, there is a real difference between ANSP resources in the US and ANSP resources in Australia: The US has many more ANSP resources per square nautical mile than Australia does and, accordingly, those in the US are monitoring much smaller chunks of airspace than those in Australia.
Aircraft that are miles apart look that way on a screen set to 10 miles range. They don’t on a screen set to 100 miles range. That’s why you’ll hear Centre in Australia alerting aircraft in the vicinity of Ooglabadooga about collision risk: those dots on the screen look awfully close when you’re monitoring an area the size of some US States.
(That said, I still don’t get why Australian RPT pilots will fly in Class G but arc up at the prospect of increased Class E coverage of what was Class G....)