But an LBW takes longer.
With a run out, you need to see two things simultaneously. The stumps and the line and there is always movement restricting views, etc. got to also watch what breaks stumps, did he have ball in hand
With LBWs it takes in turn so while you brain is processing where it pitched, the eyes are watching line of the ball. Then processing line when hits pad.
I think they need DRS as computer is the future.
There will be 3D pitch imaging at some point which will then be 99.999999999% accurate.