Well, many people believe that nothing captures the human element worse than a human, due to our inherent cognitive biases.
For example, the belief that an individual can better evaluate defense than trained experts and software is a form of the common cognitive bias called the IKEA Effect, which is the tendency for people to place disproportionately high value on their own accomplishments regardless of actual quality - and so named after the crappy do-it-yourself furniture from IKEA. (And yes, it’s really called that.)
And of course, there is the tendency for a person to believe they are immune to cognitive biases, which itself is a cognitive bias called the Bias Blind Spot.
Umpires also naturally have their own set of cognitive biases as well, which can make an already crazy difficult job even worse...