I can’t believe we could have a Class E thread without bringing up the wonderful wisdom of Voices of Reason and Class E of over a decade ago. Here is what he said from his post.
I can't belive that after all this time, you still think that a 20+ year old airspace solution is still valid, considering the technological advances in navigation, surveillance and communications. The problem you (amongst others) have is that you still think the reason for airspace is that same reason it was all those years ago. Technology and the airspace user dynamic has moved on. The reason for airspace has changed, and the answer is moving away from the airspace classification system.
The solution is airspace with performance requirements for operation. This includes surveillance/comms/service requirements for the ANSP, as well as equipage requirements for operators. In order to get to these requirements we only need consider one fundamental question. What do we need airspace for? (i.e what problem are we trying to solve). The reason for airspace at Ballina / Mangalore / The Pilbara is not the same. Therefore the solution at each location is not/will not be the same.
Class E is last century's answer for a modern problem.....and its obsolete. Voices of Reasons' post has not aged well and I think you'll find that large pieces of airspace in the US are not as they were when that post was written, nor is ATC or user sentiment.