LA is a tough one for this because it’s so spread out. San Francisco has a famously amazing BART system but the city is also very tiny compared to what most people think of as “LA”.

Depending where you live and where you go, LA Metro can be useful. I use the Metro quite often, and I know the bus system is pretty expansive as well. They’ve also consistently been adding new lines and stops including a way to get to LAX via Metro. So it’s not like improvements aren’t being made.