Singapore is also serious about enforcing their borders despite nearly a 100% employment rate. Repeat violators can get caned before being deported. Serious lifetime scarring on your butt tends to be a very powerful disincentive to not apply for a proper visa.
I felt so safe strolling streets in Singapore. There is virtually no crime. I saw sign posts everywhere saying “Singapore has death sentence to drug dealers”.
And you are exactly right about Singapore’s immigration policy. Foreign workers receive a 2 year work-permit only if there is a job opening for which a Singapore citizen is not available. Workers are careful to cause no violations since the jobs there pay better than other places. AT the end of 2 years, the worker must re-apply for a new work permit.