Giving anyone who shows up and claims they are homeless $30K is the cheapest and most effective way to solve the problem? It sounds like the most effective way to rob SF of its treasury.
As parent pointed out, they're already at 40k+ per person at the moment. Why would lowering that rob them?
Because more people would apply. Giving away money doesn't just attract people within your city's borders only.
"30k spending per person" does not mean each homeless person gets 30k. This money goes to all the workers who go through papers, work at shelters, office people to write papers to try to get more money from the federal government, and all sorts of other bureaucracy.
Almost none of it goes to the homeless people themselves.