But homelessness is complex! Thinking of Cambridge in particular, there is 3 homelessness shelters that I can think of off the top of my head that highlights this.
All completely different but great places in theory. They offer shelter, food and support. But the reality is much, much more complex. It's not as simple as just finding empty houses and filling them with the homeless.
Would you want someone taken off the streets and put in a vacant house next door to you? Knowing there's a high possibility they are dependent on drugs/alcohol/prostitution? Would just housing them be enough, or would you want to know they have had extensive counselling, rehab and support on how to live their new way of life.
The rules are different when you live on the streets. It's not easy to adjust to living within a caring community and being recognised as a human being.