The incarceration rate of the USA is 541/100k:
https://www.prisonstudies.org/country/united-states-america
The incarceration rate of Singapore is 164/100k:
https://www.prisonstudies.org/country/singapore
The homelessness rate in the USA is 19.5/10k. The homelessness rate in Singapore is 1.9/10k.
https://en.wikipedia.org/wiki/List_of_sovereign_states_by_ho...
Singapore doesn’t have a homelessness problem because they build as much public housing as possible, sell it to citizens at a massively subsidised rate, and follow up with schemes to rent to people who fall through the system for practically nothing.
If you want to reduce homelessness, you need to build a large volume of housing. San Francisco is doing the exact opposite and getting the exact opposite results.