The data doesn't really back this claim up. There are parts of the country where drug use is very high, and yet they don't have as many homeless people per capita as SF. There is a very clear correlation between homelessness and house prices, and not a clear correlation between drug use and house prices. Additionally, the mere fact of being homeless often results in increases in mental illness symptoms and drug use, so trying to get people to not be drug addicts while not giving them a home means you aren't taking away what is often one of the biggest causes of their drug use.
https://www.sightline.org/2022/03/16/homelessness-is-a-housi... https://www.theguardian.com/cities/2019/jun/03/its-a-miracle...