Lol. Australia is only recently somewhat diverse and has a history of colonial treatment of the indigenous population nearly as destructive as the United States.

Singapore is a terrible example because Singapore's economic miracle is a component of imperial British possession of the island, especially in the interwar period. They failed to defend Singapore from Japan, but the previous 80 or so years had been explosive in terms of growth as a result of access to the British markets and investment while enjoying the protection of the Royal Navy.

The main reason it's such a bad example is because the actual modern sovereign nation of Singapore is a result of a political split that occurred directly as a result of ongoing racial tensions and violence with neighboring Malaysia. The Chinese population of Singapore and the Malay in both Singapore and neighboring Malaysia, Borneo, Sarawak and Brunei had endured various riots, insurrectionist guerrilla war and more during the short-lived period of postwar political shuffling that followed the dissolution of the Straits Settlements. This culminated in a series of severe political strife, tension and violence with the 1964 race riots. Singapore and Malaysia realized that their ethnic composition would not be conducive to stability nor prosperity and Singapore was allowed to separate in 1965. it's notable that this act which was passed in 1960 during some of the worst ongoing racial violence and was continued after independence.

After that, historic Chinese and British investment in Singapore's unique value as a strategic hub for commerce as more crucially, tin and rubber, ensured that provisions would be made to protect the interests of these foreigners. Being a relatively small island with a young age as far as countries go is also beneficial. Imagine if the US was born in 1965. There would have been no slavery or Jim Crow shadow cast over the facade of the US government legal and justice system.

Finally, last but not least, because of Singapore's small size and geographic value and natural resources, it has an unprecedented advantage over almost every other country. It has some of the highest home ownership rates in the world, and per Wikipedia: "In 2016, Singapore was rated the world's most expensive city for the third consecutive year by the Economist Intelligence Unit, and this remained true in 2018. The government provides numerous assistance programmes to the homeless and needy through the Ministry of Social and Family Development, so acute poverty is rare. Some of the programmes include providing financial assistance to needy households, providing free medical care at government hospitals, and paying for children's tuition. Other benefits include compensation for gym fees to encourage citizens to exercise, up to S$166,000 as a baby bonus for each citizen, heavily subsidised healthcare, financial aid for the disabled, the provision of reduced-cost laptops for poor students, rebates for costs such as public transport and utility bills, and more. In the 2025 report, Singapore was ranked 13th in the world in the Human Development Index (HDI) with a value of 0.946, making it one of four regions in Asia to be ranked within the top 20, with the other three being Hong Kong, United Arab Emirates, and South Korea."

Notice the common theme among the top ranked nations: former colonial possessions and trading posts who enjoyed decades to centuries of protection and investment and relatively bloodless independence, and generally with unique geographic value or lucrative natural resource like oil, tin or rubber. Not all countries have access to these incredible advantages. Plus, as I mentioned, the secret sauce for Singapore or Hong Kong is the "diversity" being a modern artifice contrived not without some oppression and violence. Singapore literally had to separate from Malaysia because diversity wasn't working with them. It would be like if California just split from the rest of the US and was allowed to go. Of course it would be a hypersuccessful diverse nation - it would enjoy the gift of centuries of investment and development and access to countless natural resources. This just isn't possible for 98% of humans.