Have you actually been in sf traffic in the uber/lyft world? My observations from my life:
-Double parking everywhere waiting for pickup / dropoff /routing. Blocking car and bike lanes.
-riders getting out into traffic
-erratic drivers (new to SF, easily lost)
Its pretty terrible.
If they painted their cars yellow, and made them pickup and drop off at corners / out if the flow of traffic things would be way better (imho).