Global labor arbitrage is a huge component in S'pore's economy, so in addition to importing talent for it's more productive industries, S'pore is an attractive destination for less developed SEA and South Asia regions who arrive on a temporary pass for manual labor or domestic labor for a comparatively low wage that translates to comparatively more back home.
A major issue regarding this is these communities' isolation and dependence on their employer during their time in S'pore, with a lack of options or recourse should issues arise.
M'sian nationals, especially Malaysian Chinese, to my perception, typically work the same industries as the citizenry, and seem to be favored for permanent residency and citizenship. The citizenship process is a black box, but it is generally observed that Malaysian Chinese are the most likely and fastest to get citizenship, and it is speculated that it is for reasons of cultural affinity and racial quota.
> without the apparently corequisite skyrocketing inequality
then, apologies.