Earlier quoted context omitted.
This is true, we have the ability to house every homeless person. There are more second vacation homes than homeless people. Why not just move them in? I'm not even talking about the ones available for rent - just the ones sitting there empty.
As far as I understand, we do have the physical capability of housing that many people, but a significant number of the homeless are drug addicted, have mental illness, or both, and attempts to provide housing in mass like that leads to many of the houses becoming filthy and/or damaged. And who would want to give up a house for that? Homelessness can't just be solved with a housing band-aid, but needs to be addressed…
Baxter, A. J., Tweed, E. J., Katikireddi, S. V., & Thomson, H. (2019). Effects of Housing First approaches on health and well-being of adults who are homeless or at risk of homelessness: systematic review and meta-analysis of randomised controlled trials. J Epidemiol Community Health, 73(5), 379-387.