For who? How's that working out for the 1/3 of Singapore who is completely ineligible, yet pays taxes into the public coffers?
Singapore is unique in that they have a massive well (proportionally much bigger than US) of workers paying taxes who are ineligible for much of the fruits of those taxes. Only the 2/3 with Citizenship or PR can meaningfully get public housing.
I'm sure about any nation could have more affordable housing if they have endless wells of guest workers who can shoulder the cost without yielding that benefit for themselves.
If you're talking about providing housing in a country that had little quality housing 70 years ago, then yes, it's successful.
If it's providing affordable housing for young people, then I'd challenge that. You can't even apply for public housing unless you are married (otherwise wait until after you are 35). The government overbuilt before, so now it's a 4-5 year wait after you win a lottery to get a house. People are still pumping real estate like crazy and the average home in the resale market is >$1M now (which is a 3 bedroom, 100 sq m apartment with a 99 year lease).
Singapore is stuck in the exact same situation as every other developed country - housing is an asset that the middle class expects a healthy return on, yet increasing costs are a barrier to new owners.
Which is a huge success.