There are two decisions when driving: go ahead around an obstacle or stop. Even as a human I do not need super high resolution to identify the objects asround, as long as I can identify if is in my path or not.

While our eyes can do that pretty reliable, we are organics and get tired - how many hours one can drive until this becomes almost imposible? I had a situation where I would hallucinate and and start believing something is in the street do I did a full stop - nothing happened, but was quite intense. Imagine the other way around - not stopping and hitting something.

A normal radar + some low level ASIC programming would do that without geting tired. My Audi from 2014 is quite good at that and I actually rely on this feature all the time.