There’s empty houses in SF. Your point? The rent controlled 5 bedroom that has the same price in 1999 for the single renter doesn’t feel burdened, if they could use the existing housing and rent at market value, more people will have housing and the government will save money.
You’re assuming homeless who want to live in homes don’t know how to find cheaper housing and must be able to walk to work or that they can commute to work.
Not everyone that works in NYC lives there, and you haven’t been to Detroit recently, you’re very unfair to its recent astronomical changes, it’s a lot more expensive than you’re probably inferring from decades old movies.