Based on your argument, there would be no businesses in AU and all developed countries
Singapore is not Australia or NZ.
While OZ has minerals, dairy, fruit, meat, tourism, marine industries etc which are collectively worth billions of dollars annually and support industries have to be located at source, Singapore is nothing but a 695 sq km lump of clay with no natural resources and no hinterland.
All Singapore has is the collective will of its inhabitants. People and people alone add value to the Singapore economy. It has nothing that it can dig out of the ground or cultivate in a field. It can't survive if it operates as a country. It has to operate like an efficient company or it will go broke.
Are you really that clueless regarding how vulnerable the country is or are you just pretending to be ignorant for the sake of discussion?
Let me tell you a bit about NZ... it has a minimum wage and expensive labour. As a result, it has lost almost ALL it's manufacturing capabilities. Fischer and Paykel used to employ tens of thousands. It now does all its manufacturing in China and Mexico. Most home grown NZ manufacturing companies have long since closed shop.
The finance industry here is a joke. The turnover of the share market and the forex market is 1/10th of Singapore's or less. There are hardly any multinational financial institutions here. What's the point of setting up in a backwater where taxes are high and government regulations stifle the quick and easy transfer of capital?
However, NZ is still a reasonably rich country because it has dairy, forestry, meat and some mining and a huge tourism market. Without that, the country would now be 3rd world.