It apparently cost between $30k and $60k to house a single prisoner in the US. So you have a choice: you can spend those $30k to $60k putting a homeless person in prison (not solving the problem), or spend the same money fixing the actual problem (treating it for what it is: a mental/health issue) or perhaps spend the money cleaning up the streets and provide places for people to use drugs safely. America so far has always chosen the least effective, most cruel way to pretend to solve the problem.