Example: When my sister, who lives in Los Angeles (the state's largest city) wants to take a train to Sacramento (the state capital), she first has to take long-distance bus to a city in the Central Valley. Same if she takes the train from LA to Santa Cruz (with the result that the trip is 11-12 hours by train compared to around 6 by car). The passenger trains just aren't very convenient for most locations. There is a good interurban system in the San Francisco Bay Area (SF, parts of Silicon Valley, Oakland, Berkeley, ec.) that carries a lot of commuters. I think a lot of places that are now bedroom communities for SF, San Jose, and LA were nowhere hick towns when the rails were laid down.
Not to mention that California is the absolute home of car culture.
Think: drive-through funeral homes (way way before Covid).