The city has no real "center" if you will.
Back in Chicago when I switched jobs I basically just rode the metro for an extra 5 minutes.
If I really wanted to I could of gotten off at the same train station, went to the cafe I liked, and walked 10 minutes to my new office.
In LA you can easily have one job in Santa Monica or Venice and end up needing to switch to a job in the valley. Your commute can go from 20 minutes to 60 or 70 each way.
As is car ownership is a horrible burden( particularly in high traffic areas, living in a suburb/ slightly rural area and coasting to work could be nice). Driving is really dangerous and stressful too. I'd rather read comics on a nice train ride into the office.