The last 10 years has seen CA spend more on homelessness than ever before, and more than any other state by a huge margin. The result of that giant expenditure is the problem is worse than ever.
I don't want to get deep in the philosophical weeds around human behavior, techno-optimism, etc., but it is a bit reductive to say "why don't we just give homeless people money".
In CA this issue has to do with Gavin giving that money to his friends who produce very little. Textbook cronyism
CA didn't spend money on solving homelessness, they spent money on feeding, sustaining and ultimately growing homelessness. The local politicians and the corrupt bureucratic mechanism that they have created, including the NGOs that a lot of that money is funneled to, have a vested interest in homelessness continuing.
What else happened in the last 10 years in CA?
Hint: https://fred.stlouisfed.org/series/CASTHPI