I disagree. Or at least I do for myself. It is the same reason studying physics theory alone is sometimes not enough to "get it". Often to really learn something you need the dirty real-life demo.
You don't have to excessively see hours upon hours of such footage.
But a single harsh and gruesome traffic death footage sure as hell made me more careful in traffic. No amount of crumpled car metal was going to properly internalize in me how sudden and unexpected death can be and how fragile life really is.
Not being aware of this is also a cause of traffic accidents. People should be more careful driving.