I had to pick up my brother-in-law and his wife at the international terminal Thursday night, early on in this Uber/Lyft move. It was a disaster trying to get into the airport itself because rideshare vehicles were clogging the entry roadways. I was coming from the south and traffic trying to get into SFO was stopped on the freeway about a mile or so from the SFO exit. I continued north, past the airport and came back in the opposite direction (from San Francisco) and I could reach the I terminal. Roadways into T1, 2 and 3 appeared to be moving okay once traffic passed the rideshare lane.
Traffic at the I terminal was its usual chaotic self with people stopping anywhere they damn well pleased. I’d estimate roughly 60% of the cars I saw were rideshare vehicles.