I think the problem now is that individual waymos are ok on relatively narrow streets, streets with hills, being cautious about pedestrians and cyclists, etc. The most frequent issues I notice in SF now are around waymos interacting with other waymos. This particularly involves deadlocking when trying to navigate around each other in tight areas. I've seen this with multiple waymos trying to get around a double-parked delivery van, where a waymo trying to go around blocked a waymo in the oncoming lane and they both stopped. I think this is also related to the issue of waymos honking at each other in their own private parking lot because they were getting in each other's way.