While it is common for people in urban areas of Europe to completely do away with their car, public transport in the US is infamously bad -- partly undeservedly so, when you look at cities like New York that run a successful mass transport system that's basically up to par with other cities of considerable size.
But of course, in the Bay Area, millions of people meet massive suburban sprawl, which is an absolutely toxic mixture for fast and efficient public transport. Still, the commuters are being offered several options depending on where they live. The one closest to where I live is the VTA lightrail system pictured here. It's sufficiently modern (and clean, and safe, at the very least during commute hours) to be a good commute option. Sadly, it is comparatively (and sometimes inexplicably) slow. At best, it's a wash between VTA and driving (when commuting alone), or easily takes 1.5-2 times as long as a commute by car (when commuting with >= 2 people, who can access the "commuter lanes" on the freeway). For cost, the picture is similar.
That commuting by public transport is not the downright best solution on all fronts makes me sad.