By contrast the prior #1 most liveable city - Melbourne - has grown from 2 million 30 years ago to 5 million currently, forecast to get to 8 million by 2050, all due to mass immigration. Livability has fallen directly in line with population growth.
I've lived in a lot of cities around the world and think there is a 'sweet spot' population number: big enough to allow the provision of niche services and the agglomeration of talent, yet not too big as to introduce costly dis-economies of scale (usually through very expensive housing and transportation.) That level seems to be about 1-3 million.
The opposition to mass-immigration (the country is growing at about 1.6% annually, with the same annual level of immigration as the UK, a country with 3x the population) is completely justified and it is not in the long-term interests of the country or of individual Australians.
Its not only the formal mechanics - the whole system is rorted, with a lot of fraud. A Chinese businessman bribing federal politicians for citizenship is a current news item.
Finally Australia makes its way in the world by mining and selling off its fixed endowment of minerals. The rest of the economy is not particularly competitive, mostly just domestic services and real estate. More people means a smaller slice of natural resources per person. This is not theoretical - wages are flat and cost of living pressures are high in the country. Public healthcare, education and transportation are all overcrowded.
However, Vienna isn't without its faults. In Vienna you have a huge segregation between better and worse off people. You have a lot of low income people living in places like the 10th district and people in higher income brackets living in Doebling for example. This is counter productive in the long run as it will slowly create "ghettos" and mono cultures within the city. In London the wealth gap is much higher than in Vienna and yet people live more closely together. You can walk down a millionaires street one second and in the next moment be surrounded by council housing. In my opinion this is much better, as it prevents places from turning into ghettos and helps to keep the city in a sane state. There is a lot of gentrification happening in some parts of London too, but this is more of a side effect of the consistent growth rather than segregation.
The other problem which I see is that the average person in Vienna does not own any property. Most people are in rental properties for most of their lives and they mostly rely on a future state pension in order to retire. To me this is a fragile system, because it forces the country/makes it reliant on a highly taxed middle class. It is extremely difficult to prosper from middle class to being rich in Vienna - for the better or worse.
The entry barrier to creating a new company and the huge amount of regulation also makes it extremely unfriendly for startups and innovation.
Long story short, socialist cities in a capitalist Western country only thrive as long as the population is small enough and stable for a long period of time. It takes many years to build new schools, hospitals, GPs, train lines and bus routes, whereas it takes only a few weeks for an individual family to settle in a new place. If a city undergoes a massive growth in population then it doesn't even matter if everyone who moves into the city is a hard working high tax paying person, because the new money which they bring in will not be able to keep up with building the necessary infrastructure to comfortably accommodate everyone. It will take decades to catch up and only if there ever will be a slow down of growth, otherwise it will be a never ending chase.
I'm living in Vienna, Austria which is a city consistently rated to be in the top 5 most livable cities by multiple independent evaluations.
How did that happen? A strong sense of ownership and infrastructure thinking over a _century_.
Just to mention the obvious, property prices do not exist in a vacuum and cities where property prices go through such a steep and continuous rise as in London, Moscow, San Francisco etc. are not a reflection of desirability or market forces but rather the total abdication of planning and responsibility from the local authorities.
There are dozens of things local leadership can do to fix infrastructure and living standards issues, never let anyone tell you otherwise.