Humans work with much more than just eyes. We subconsciously move our heads in case of uncertainty in the stereo vision algorithm and have pretty good IMUs. And yet, everyone has the experience of wrongly focusing on a repeating vertical pattern (vertical blinds or coiled cord for example) and getting disoriented. And every experienced driver has experienced at least some of the following: a moment of glare from a wet road, driving into a sunset, snowy road with curves in flat lighting conditions, dirty windshield/headlights/backup camera.

All of those are challenging for humans and and probably even more challenging for computer vision with cameras only. But except for the last point, all are obviously improved by lidar.