Please try to look a little harder.
One international airport for Melbourne (and basically Victoria) out at Tullamarine is perfectly fine. It has room for expansion, it is well-positioned geographically and there are big benefits to having it as a central hub as opposed to spreading out airlines and domestic/international operations between airports. To a certain extent that is true, but Melbourne is, and will remain, a second rate airport until it has more runway capacity. Two additional runways have been in semi-planning for at least 40 years. For many of those years there were signs near the airport showing where the proposed runways would be. Progress to date? Nil.
Click through to the (large pdf warning) 2018 Master Plan. Go to page 142 of the document. The third runway at YMML (southern East-West runway 09R/27L) is well into the planning and approval stages and has a projected opening date of 2023, along with widening and extensions to existing East-West runway 09L/27R.
The idea is to decentralise Victoria's population, and not keep growing Melbourne.Melbourne centric is not the way to think unfortunately, however much that may hurt! Smile Avalon would be a good second airport for Geelong and the region as it grows, as well as western Melbourne. Made even more attractive with good public transport access. A third airport out east? maybe in 50-80 years! Also, a second airport introduces competition, which helps lower fares. Everybody wins.
Decentralisation policy in Victoria (and Australia in general excluding Queensland) has been a total flop for the last 50+ years. A handful of industries have been moved to the regions, to a small degree of success - only to fall victim to a much larger national trend of deindustrialisation. Government services have been moved to the regions and it has largely been a disaster - moving the TAC to Geelong being a perfect case study
- only 100 of the 700 public servants stayed along for the ride once their contractual obligations to stay with the organisation while it moved to Geelong expired. And Geelong is the "ideal" place to decentralise according to the traditional set criteria - it's got a large population and is also a relatively short distance by road (and frequent rail!) to Melbourne.
What is the most widely touted success story of decentralisation policy? Albury-Wodonga in the 1970s. That's roughly 40-50 years ago, with very different industrial policy settings (highly protectionist and a much heavier degree of Government support/involvement). I challenge you to come up with a more recent example of successful decentralisation policy (as opposed to maintaining an already very decentralised economy/population environment, like in Queensland).
Like it or lump it, Australia's 'capital' cities have large populations and high growth rates because people want to be there. There are agglomeration benefits by having organisations and industries all located together. People and their social groups want to stick together for the large part - this is largely the reason why attempts to resettle refugee migrants into regional areas has also been a failure in a lot of places unless it is done on a wholesale instead of piecemeal basis (Nhill is a good counterexample
The real challenges are figuring out:
- Decentralisation policies that will actually work and provide organic long-term economic & population growth in regional cities, as current attempts are ham-fisted and ineffective as I pointed out above
- How to keep fitting more people into our capital cities without totally destroying their livability by turning them into an all-consuming blob of urban sprawl that spans hundreds of kilometres in every direction
- How to retrofit our capital city suburbs where there is an existing pattern of poor livability (largely a function of the car dependence of residents)
- Where railways (and public transport more broadly) fit as potential solutions to all of the above challenges. There are some rail projects that will be beneficial and some that will be expensive and ineffective (like, I must say, high speed rail projects in a broad sense).