I actually know a fair bit about Australian visas.
Fact - you do not need permanent residency to access Medicare.
Fact - The reduction of issued visas recently is due to the reduction in "Skilled Worker" applicants. The planning level remained the same as other years (actually slightly increased) just not enough applied.
Fact - if you are serious in moving to Australia you need to consult with a Registered Migration Agent. I know of around 6 that I would happily recommend as very good.
Fact - There are far better places to live than Sydney. But for the unlucky, many companies have a "Sydney Allowance" that assist a bit.