I’m only familiar with San Francisco, but every time I’m there I see that most people use Uber and Lyft instead of the bus.

Buses are under-utilized, but walking and various forms of wheeled transportation (motorized longboards, those one wheel things, bikes, scooters, etc) are popular.

San Francisco is only about 7 miles wide. You can walk from one side of the city to the other in about 2 hours. When I lived there, I walked almost everywhere. The only times I did otherwise was when it was a really long walk (over 45 minutes), or I needed to be somewhere fast. The bus will not get you anywhere fast, it's only about twice as fast as walking. I think that's why a lot of people use Lyft. The buses are actually quite nice inside imo, they're just slow. Plus the stigma that only poor people ride the bus.

You're lucky if you are able to live and work in SM or DTLA. Majority of people do not.