The setup at SFO is currently quite annoying (Lyft/Uber require you to walk 5 mins to the garage roof, and drivers need to park/wait 5-10 mins away, so there's always a substantial delay). Taxis get the privileged parking spot immediately outside arrivals, but if it's busy you might still need to wait a bit.
I've been wondering for a while why Waymo can't offer a semi-managed solution to SFO to dynamically manage load, have just the right volume of cars inbound, maximize parking utilization, etc. with all of the nice intelligence that an app-based system would enable.
It feels like you should be able to have a buffer of cars waiting right at the curbside, and automatically refill that buffer on short notice depending on observed or predicted demand.