The robotaxi company now covers 315 square miles in Metro Phoenix, making it “the largest autonomous ride-hail territory in the United States” — a totally real and not-at-all-made-up superlative. Even so, the incremental growth shows that Waymo is getting more confident in its driverless capabilities. But some argue the real confidence is when it can start adding multiple new cities in a year. And Waymo still feels like it’s not quite there yet.