California was a paradise in 1970. Today it's much closer to hell. In my opinion.
There's one trick to solve both these at once, while simultaneously helping the environment: more mixed-use walkable housing close to job centers.
Homelessness and traffic are policy choices that we've made because the last generation, the one in power that refuses to see the errors of their philosophy and refuses to budge an inch, consciously made the decision that after a population boom, they wanted to keep people out. Which results in the long commutes, which causes even more traffic.