If you took the world as it is now and left everything the same except that every car was a waymo and there were no human-driven cars left, I would be ecstatic. Humans are horrible drivers and some of them are downright murderous. If every car were a waymo I could even imagine letting my kids bike to school in the bay (where I used to live), which I wouldn't dream of now.
But I think the second-order effects of self driving cars could be terrible. It removes any incentive not to have an incredibly long commute (exacerbating sprawl), and so far every time there has been a situation where the needs of walkers and cyclists were pitted against the needs of drivers, drivers won. I think the same will happen with self-driving cars, and people will be made to wear beacons just to walk across the street.
NotJustBikes discusses this well here https://www.youtube.com/watch?v=040ejWnFkj0
But if we have proper regulation (pretty unlikely I would say) and use things like waymo to stop humans from driving (remember, drivers are the leading killers of children in the US!) that would be great.