Most of the homeless people I see, the ones who are literally pitching tents on the side walks, sleeping on boxes, defecating anywhere and everywhere, passed out on park benches at 3 in the afternoon, are almost certainly not going to be benefited by lower housing prices.
These people could not afford nor likely ever would afford, a house that cost literally anything. Most of these people suffer from a mental illness and/or a drug addiction which makes holding down a job unlikely to ever happen. What they need is publicly funded mental health hospitals, like the ones that were destroyed in the 80s.
Of course high housing costs are a huge problem, but I just don't think they tell the whole story when it comes to CA homelessness. There's an elephant in the room that far too many people don't want to address. It's the aforementioned population of people who either can't or won't work and the solution we have for them right now is the street.