Yes - even for Waymo anything more than 6 to 12 months would be dragging their foot for too long.About 3.5 years.
But in Phoenix, they had no experience with ride-hailing and just starting their 4th Gen FSD. And covid delayed things a bit too. I doubt it will take that long in SF. Waymo now has the benefit of all the experience in Phoenix and the 5th Gen FSD which is much better than what they have in Phoenix. In the Autonomous Progress thread, I predicted "6-12 months" before they open it up wide to everybody with no NDA. I could be too optimistic. But I still think it will take much less than 3.5 years.
Infact when I just read the headlines about Waymo starting in SFO, I thought it was already driverless and paying customers.
What we really need to know is - how long does it take Waymo to expand to n+1 city. That will determine whether they can ever be successful.