There is one benefit of having people in the loop in that they come with a completely independent set of sensors for flying the aircraft. Look at the recent iss

There is one benefit of having people in the loop in that they come with a completely independent set of sensors for flying the aircraft. Look at the recent issues where the single sensor on the Boeing Maxs crash the aircraft. They're far from perfect for sure though(see the times people did the opposite and ignored the correct sensors causing a crash) but there's a definite benefit to having two completely different systems monitoring the data. It's unusual to see that level of safety differentiation, not only having multiple copies of a sensor to take measurements but multiple different designs and types of sensors measuring the same thing to avoid correlated failures.