waymos don't remove lanes of traffic, they remove parked cars and parking infrastructure, which is still pretty huge. In many suburbs, parking is the real bottleneck not traffic.
They still have to park somewhere... And the service (Waymo or a future competitor) that has it's cars closer will win more customers or can charge higher fees for faster service. The parking infrastructure might move a bit. But it won't disappear. I'd wager it'll even increase.