In SF, the northeast quadrant has most of the good public transit. Does that not fit your needs? And, I disagree that Taipei and Chengdu are significantly cleaner than SF -- about the same level of grime in my experience.
No. The public transit there hardly goes anywhere in reasonable time. It takes a good 40 minutes just to get across it. Many times I've walked faster to my destination than the public transit estimates. The Muni trolleys get stuck at intersections and red lights and don't move faster than cars. The BART only goes down 1 smelly street. I'd spend 2 hours round trip (1 hour each way) just to buy a vegetable from the nearest Ranch 99. That's not city life.
Most Asian public transit systems blaze past all the cars on the surface. They actually save time from driving.
Even I, a non-homeless tech worker, have been forced to pee in the bushes next to a sidewalk in SF, because I was refused restroom access by 5 businesses in a row and I was already getting heart palpitations trying to hold it in.
I have never been refused restroom access (and there was almost always a public one within 100m at all times) in most modern Asian cities. Or even south bay (which is basically Asia), people are usually nice here about letting you use restrooms.
