Well I'm not an Airspace expert, only a humble end user but I've already suggested a few very basic things earlier.
VHHH CAD and the CAAC are currently re-designing the whole Pearl River Delta airspace to improve the flow and amount if traffic between VHHH VMMC ZGSZ and ZGGG. They have real problems with layout and different countries proceedures all in a 50 mile congested plot of land, but are trying to work them out to mke it smoother ( one eg is Aircraft arriving into VHHH fom the mainland are currently faced with 100 extra track miles )
Surely Perth ( as one Aussie eg ) with only 1 major and 2 very minor Airports could better design their airspace layout with regards to SIDS STARS to better flow the traffic????
Anyway, I guess the ATCO's in here dismiss my thoughts as amateur but I'm still entitled to express my thoughts because it seems to me and many other Airline crews that those places seem to move it along much better.
I guess like most other things in this world it comes down to dollars.......