Anyone can do something that's going right. It takes an expert to still succeed with something goes awry.
I meet CEOs all the time who admit that they thought they were pretty hot stuff until things started going wrong with their business, and suddenly they realized they were in over their heads. The same goes, in a much more tangible way, for dentists and surgeons. Most anyone could be trained to delivery a baby. But my wife wanted to do it in a hospital with a professional staff just in case something went wrong. Most anyone can install a cable box, except when it doesn't work and we wish we'd scheduled the cable guy after all. And we can all configure our email properly, except when we can't and wish we had an IT guy around.
I've written about how experts do it better, but they also have a wellspring of information that you don't, and you both hope never has to get used.