There are 16,000,000 empty homes and 500,000 homeless. Office buildings aren't going to be solving any real problem other than the people who own the building being shit out of luck
More supply is more supply. It'll probably drive rent down a bit, assuming the plan works. This makes little difference to unemployed homeless people and does nothing to address the fact that many wealthy people see homes as a tool to secure their capital, but it's not nothing. Hopefully it will help some people who are on the brink be a bit more secure in their housing.
The corporate landlords will just buy them up and let them sit empty the way they have done with at least 4 highrises that I can think of off the top of my head in downtown San Diego. Sure they have rented some of them, but the majority of those buildings sit empty.
Please don't provide this stat without context. It just promotes cynicism and despair. Reality is complex, and our solutions are going to have to be complex.
Many of these vacant homes are nowhere near major homeless populations. But office buildings often are.