edit: apparently SF is not representative of public transit in other cities in California.
I’ve lived in both downtown LA and Cambridge, and it’s really difficult to conduct life in LA relying primarily on local rail options. Whereas in metro Boston, it’s much easier to live car-free than to own a car. The subway and commuter rail are just a superior way to get around 99% of the time. I mean, it’s not the same degree of car-obsolescence as New York, but it’s much closer to New York in that regard than it is to the situation in LA.