There must be something that makes a bunch of Colonies, a Colony Country, called Australia, a wonderful place to live, be in, thrive and exist.
Yes, our basic systems of Justice and Enterprise are based on the United Kingdom's systems, but our attitude to life and our Social structures are completely different.
Australia has always had an immigration policy, though set by an elected Government structure (do not start me on bureaucratic interference) that sets particular guidlines for immigrants, it is the laissez-faire attitude of our society that encourages individual success, this feeds into collective success, which is a Country going forward attitude.
The bedrock of the previous paragraph was the Colonial years from 1788 to around 1860, when convicts aplenty were sent here, free settlers were encouraged and arrived in droves, and the law and order and markets grew from soldiery to police, and individual orders to structured standards by group selections.
The UK, on the other hand, has in the past and even now, a structured social system, from Royalty to peasantry in the past, to Royalty to dole recipient now.
Also in the UK, land ownership has always been a contentious issue, from times gone past where only the "landed gentry" had ownership, to now citizens being able to own their own patch of dirt.
Immigration was forced on the British super power, with immigration arriving from far flung Colonies in the later 20th Century, a result of Colonisation and giving basic right under British rule to Colonial citizens.
The attitude in Australia has been cemented as a she'll be right and whatever may be viewpoint, and mostly a reasonable distrust of those in power, far different to the English deference to power that comes from a structure class system.
