We seem to forget that airspace reform and/or change is not a one-off it is a necessary part of a dynamic aviation system.
Prior to alphabet airspace reform had already started in Australia where, in alphabet terms, we had large amounts of Class B and enormous amounts of Class F. Equivalent Class B was being whittled back to equivalent C by stopping the requirement to separate VFR aircraft from each other in CTA and as far as I am aware no-one wanted to pay for the Class F services, otherwise called FIS/AFIS.
Then ICAO airspace arrived and like everyone else in the world we named all the airspace we then had and changed a few rules to comply with the ICAO classification requirements. Two areas where we did not are Class G and was the GAAP airports, now changed by CASA decree to Class D.
So at the moment for en-route we have settled on Class A (no-one seems to object) with some Class E underneath it (an experiment?). This leads to Class C down towards a controlled airport followed by more Class C or Class D to the ground depending on the amount and type of traffic.
This is what most of the world has other than countries that have been subject to US influence and have Class E overlying Class B, C, and D. We have not gone there yet - but we might. (I haven't mentioned the enormous tracts of airspace fenced off by our military - that is probably a subject for a different thread)
Under all of this we have Class G but with mandatory ATC provided IFR traffic to IFR aircraft - almost Class F. We also insist that all aircraft within 10 NM of a certified airport call on a frequency, often a CTAF. (There are rules for non-radio aircraft however that is out of scope) Strangely enough I don't think a certified airport is required for RPT operations which you might think was why there are mandatory radio procedures.....
An issue has arisen where some airports are felt to need something more but do not warrant a Tower. For some reason very few so-called UNICOMs (another US word) have been created by the airport owners. (The AIP states that such a service can pass weather information if approved by CASA, but not traffic information). I suggest that once again it is because no-one wants to pay for the service. Two airports, soon to become three, have what mgahan calls an air traffic advisory service, what we call an AFIS or CA/GRS, they can both give directed traffic information and there is little difference between the two.
We are still in the transformation stage, mainly because we cannot agree on an airspace "model" and from observation most discussions on the subject end up being a horse trading exercise much like enterprise bargaining.
I'm sure that there is more change ahead and threads like this add to the spread of ideas and opinions. We do not have to follow the US model or any other model but what we do have to do is create an airspace model the country can afford. Hopefully it will also provide an equivalent level of protection to fare paying passengers across the continent.