People aren't built for repetitive motion.
They tire, they make mistakes, they slow down, and they develop physical problems after repeating similar motions over time. Picking is a very un-ergonomic activity, so reducing the worst aspects of it are key to any organization that is concerned with injuries, speed, and productivity. And it's also the most economic way to execute these operations.
People are relatively slow when compared to the kind of speed and precision a robotic picking system can offer. When you take a component from point A to point B, over-and-over, and the motion is within a similar range, robotic pickers gain a tremendous advantage over manual solutions. High speed, robotic picking systems have also become more affordable relative to the high cost of manual solutions.
With modern vision systems, conveyor tracking technology, and precise, agile robots that can pick & place at rates up to 200 per minute, it's becoming increasingly clear that a robotic solution must be considered for fast, competitive operations.