The reality is that with or without LIDAR, the entire problem space is very far from solved, and the distance to close has a lot more to do with prediction, decision-making, and abstract representation. By the time these things have come far enough that full self driving cars are a reality, it's very likely vision will have progressed as well.
The whole self-driving race is a leap of faith that there is some mid-point between "current state-of-the-art" and "full human-grade general intelligence" that is good enough to safely drive a car. Nobody knows whether that's actually true. So far, all we know is that general low-level sensorial awareness isn't a sufficient condition for tolerable driving. We all suspected this was the case, and so now comes the long tail of discovering just how much more behavior you have to add before you've sufficiently emulated human driving. These systems are so complicated and the interactions so numerous that the horizon is very foggy. It's POSSIBLE that you don't have an acceptable driver until you're basically doing human-level reasoning. Nobody knows.
The point is that if you need a significantly deeper level of inference, prediction, reasoning, world state estimation, etc. etc., then the LIDAR will end up irrelevant, because the processing chain will be so sophisticated that camera-only input is easily sufficient for the sensing aspect. And if that's the case, camera-only is by far preferable because it is cheaper and simpler.
Saying that you need LIDAR is just as unfounded as saying you don't. And it has the downside that you're doubling down on a more expensive technology that is demonstrably unneeded by a sufficiently sophisticated intelligence (i.e. humans).