Singapore, although sterile, is more stable all around. Especially for having better career prospects
Bangkok is likely more cost effective for retirement or having a nice holiday.
Spent more than 4 years working and residing in Bangkok and decided to return to my native Singapore. I did meet many Singaporean expats. Most of them were married to a Thai. Some had been based there for long periods and returning home was not a viable option
my view is, better to earn Singapore money and spend your holidays in Bangkok. Working there is quite a different experience