While I understand your argument and agree that more sensor means easier path to self-driving, our world is now full of systems that can infer amazing amounts of data from a few sensors. This is the progress of technology.
Apple Watch is probably one of the greatest examples. So many of it's features are inferred via "basic" sensors.
On a different angle, sports refereeing is largely becoming possible due to advances in camera based analysis. We can turn 2d images into a nearly centimeter accurate representation of a playing field in seconds.