Companies like Waymo and Cruise use this kind of technology too. Unfortunately there are tons of corner cases of weird things you haven't seen before -- for example, some special vehicles self-occlude and you never get enough coverage to observe them correctly until you're too close. In general, radars and lidars used in _conjunction_ with cameras can handle occluded objects much better.

Also, to measure the performance / evaluate observations generated from this tech, you would want to compare it to a pretty sizable 3D ground truth set which Tesla does not currently have. There are pretty big advantages to starting with a maximal set of sensors even if (eventually) breakthroughs turn them into unnecessary crutches.