Imagine you are in a small time-warp western ranch town. In your travels, through whatever circumstance, you are on foot, wounded and bleeding.

The gas station is shut down. The sheriff is out chasing bad guys. The mayor is sleeping. The blacksmith is away at a smithing convention. The farmer is in a field with noisy machinery. The barber sees you, but for whatever reason, locks the door and flips his sign to closed. There is a drunkard on the street but he is not coherent to assist. A kid on a bicycle goes by, and offers to help, but his home is in the next town over, too far to walk. What are you to do?
Thankfully the doctor is in. And a doctor is exactly what you need. Thank God.

Now, how important was that farmer to you? If the barber was kind and generous, would it have made much difference? Can a blacksmith heal a bleeding man? No, not by trade. That is what the doctor is for. The best these others can do would be to give you directions but their usefulness drastically diminishes once the doctors office is found, with them, or without.