[Symmetry]

For human level driving a human level understanding of these scene from purely visual information is quite good enough. The first problem, though, is that the human brain has far more processing power than any computer that can fit in a car and probably more than any single computer yet constructed (estimating even to a single order of magnitude is hard). We're also leveraging millions of years of evolution though I'm not entirely sure how much of a difference that makes given how different our ancestral environment was from driving a car.

The other thing is that we, ideally, want a computer to drive a car better than a human can. There's a lot to be gained from having precise rather than approximate notions or other objects' distances and speeds in terms of driving both safely and efficiently. Now, Tesla has also got that Radar which when fused with visual data will help somewhat but I'm not sure how far that can get them.