Humans don’t need LIDAR to determine distance and motion because we have a visual cortex and eye that has undergone several hundred million years of evolution to be able to interpret an astonishing amount of visual information and integrate it into other senses. Even then, we are easily fooled by optical illusions or perceptual artifacts into mistaking distance and motion. Contrary to popular belief, perception of distance has almost nothing to do with parallax of binocular vision beyond a few inches and is the result of complex shape recognition and integration in the brain, the extent of which we are still struggling to understand.
I know there are a few people, Elon Musk in particular, who feel that computer vision will soon equal that of humans, but that is a conclusion borne out of blithe ignorance. Computer vision is one of the most difficult practical problems in machine cognition, and even after decades of effort by tens of thousands of researchers working every conceivable approach we still have yet to develop a system that can recognize a known 3D geometric shape at an arbitraty orientation and distance, and particularly if it is partly occluded by another object in the field of view. Recognizing orbitrary patterns, like a road lane with poorly identified boundaries, is something experienced drivers do almost instinctively but that computer vision systems have consistent trouble with.
LIDAR helps with rangefinding but the problem of synthesizing a wolrd model including inferrences of unseen parts of objects, like a motorcycle going around a truck and will appear at the other side at an expected time and speed, are really complex problems that have to be solved before fully autonomous vehicles are feasible for the reasons stated above. And while the costs of LIDAR and computer vision systems will reduce with higher volumes and advances in technology (although I doubt they will be so low as to be inconsequential of,the cost of a vehicle), the point remains that once autonomously piloted vehicles demonstrate order of magnatude improvements in safety and reliability, and offer the ability to offset the direct and indirect costs of ownership through communal ownership, subscription service, or making it available for secondary use when not immediately needed, the benefit to most people of not bearing the expense of a privately owned vehicle that sits idle for most of,the time is pretty evident, especially as other lifestyle costs like food, medical care, and housing continue to rise.