Singapore does have some advanced manufacturing, it also has has easy access to cheap slave labor from neighboring countries like Indonesia, China, India, Thailand etc etc. Its financial sector also engages in massive money laundering. On one hand executing the drug runners, on the other hand doing business with all the drug lords Myanmar. (the US kinda does the same with slave labour and drug lords). If Ontario were to build a wall between the GTA and the rest of Ontario and spend all the GTA tax dollars locally without subsidizing the rest of this vast province, then the GTA would be like a big, super rich Singapore. The rest of the province, like a frozen Indonesia.On the other hand, Singapore does not have oil or other commodity resources and is even short on water. It also gave up manufacturing, like Canada, years ago.
Either copy the solution or avoid the problem in the first place so you don't even need a solution.