LA has no unified bus system. It has multiple ones and its super confusing. Each bus makes a stop nearly every minute, making every ride impossibly long. Lack of bus lanes make for shitty traffic stuck trips as well.
It's the same in London. That's why for longer rides you take the tube. Buses are for shorter rider or from getting from/to tube station.
Let’s us Stockholm as an example: 100 metro stations and 170+ suburban rail stations, 60 light rail stops, on 2.3 million people in 6,519.3 km2 (2,517.1 sq mi).
San Francisco (Nine county, Bay Area), 33 metro stations, plus 87 additional metro stops about 200 station (ACE, Amtrak, BART, Caltrain, SMART, and VTA), on 7.75 million people, In 6,966 sq mi (18,040 km2).
The station density is nearly 2.5 times higher and on less than half the population.
Data from Wikipedia.