Because the hierarchy is very structured and it’s very hard to mid hire locals.

You imagine the first 5 years is like going to school Primary 1 to Primary 5.

Fresh graduates start from Primary 1 and slowly progress upwards.

But every year people will quit, so maybe your Primary 1 Class starting got 40 people, by Primary 3 left 20 people.

So now got shortage of Primary 3 people, where to find replacement?

One source is for other singapore B4 people to transfer to your school, but this is just playing musical chairs in Singapore, you don’t increase the total pool of people.

It’s also very rare for commercial people to transfer at staff level, because you may be downgrade rank due to lack of relevant experience and have to work under someone younger than you. And I imagine mid career people usually wouldn’t do such a career switch for a paycut and more challenging working hours.

Another source is to hire from mid-tier firms. This is one source, but also quite limited in numbers.

So the best solution is to hire from Malaysia B4, who has relevant experience, is used to the working culture and challenging hours, and from their perspective, the same rank but salary in SGD earns more money.