Successful F&B businesses hire foreign staff on S-PASS or even EP. You never wonder why some F&B business hire mostly, if not all foreigners? Those hiring locals will lose in the race.
Eg. $4000 for S-PASS and more for EP.
Every month, these staff will reimburse their boss 50% under the table. 
It is a win-win, the business get cheap labour, the boss get to reduce their business income tax obligations.