Because it isn't just about the competency, or the ability to do something with a degree of accuracy and efficiency; nor is it just speed, reproducibility or cost. it is about the experience and the emotional response, and by that I mean that having a lot of one will trigger the other.
The role of a manager is to foster an environment in which all those good things should thrive. You don’t do that from the top, or being out in front on display as a figurehead.
