[sgh]

depends on the company.
if the company has dual career path for developers (technical and management), developers will stay long because the pay is same as management role.
it means you have not worked in company that provides technical path that pays the same as management role.

no matter what, there is no lack of local applicants.
I have talked to WSG on all govt job program for IT, all IT programs with employers have oversupply of applicants.

if you have any employer who says he cannot find local IT applicants, ask him to sign up with WSG/IMDA on
hire and train program.
he can easily get more than 10 applicants for every job vacancy.
there is no need to import foreigners unless he wants cheap foreigners

Can I know are you also in IT industry? If yes how many years? It is a common known fact locals do not want to be developer forever. They aspire to be manager instead. Developer to them is like the initial years of their career not forever in that role becuz they view that role as labourer compared to manager.