There were a few advantages first, the population will be controlled, there were too much people in China that it have caused a shortage of jobs for a lot of people. In another sense, it reduced the  people applying for jobs, but at the same time, vacancy for a job may not get the best applications. As a China citizen , I understand that it was somehow unfair.

In Singapore, there were more aging population, that will cause a more old people and babies but not mid aged people that was able to work. From less child borned, there will also be a heavy load on tha younger generations that is co carry up to six people. So to have a more capable load for the young generations, there should be more babies.