Don't get me wrong, I do not want to play clever here, it's just a honest question.
Also, by the time he is already homeless homeless, he is likely no longer able to afford the fixed costs of a move. He is not getting an apartment even in small town USA if he can't put down a deposit. He is not even getting there without money to pay for the trip. He'll also likely need a car to hold any job which is another major cost.
And by the way, you said he should get a job, "any job." Now put yourself in the position of a small town mcdonalds franchise owner. Someone just moved to the town from California cough all in a sudden. He has no local connection, no experience in food service (or whatever other low skill job you are offering), probably not even an address. Why would you hire him instead of literally anyone else?
I'm not sure what your qualifications for 'reasonable' and 'capable' are, but without a support system those things are difficult to prove such that you can utilize them properly.
Let's do a thought experiment. Imagine have been evicted from your home and have no job. You have no car, no phone, no ID, no money, no credit or bank account. All of the people you know who would give you money or a place to stay or a reference have disappeared and cannot be reached. What do you do?
You could find a cash job as a dishwasher or something similar. If you work nights you can sleep in the library on in other public places. But where do you put your things? Spare clothes, toiletries, books, everything you might need to feel comfortable or to look decent has to be carried on your person, and even then is liable to become lost or stolen. How do you shower? Every restroom experience is using a public one. You can't cook meals, so you have to find free ones or buy them.
Hopefully what you got out of that is that access to things that you and I take for granted is a really big deal to someone without a home, and cities like San Francisco make many of those things difficult instead of impossible.