But also too, packed with junkies who, at best, behave erratically and at worse assault randoms.
Taking the bus around sf makes it immediately clear why (not all, but most) people who have options choose them.
People always claim this and then talk about their car as a perfect save heaven. When in reality road rage incidents are also incredibly common. People taking out their guns or starting fights. And of course generally accidents kill a lot of people.
That said, if you only look at driving in a city like SF, this is likely less of an issue.
Honestly, there aren't that many crazy people on the SF Muni/busses. The detractor for taking these services is speed and frequency.
Even factoring in parking, traffic, and bus lanes, it's much faster to drive within SF than take the bus. Stopping every 2 blocks and missing every other green light kills throughput.
My local bus stop to connect to BART supposedly had service every 20 mins, but often a bus would be out of service and the wait would be 30-40 minutes. Unless a bus was right there, it was faster to walk.