I think that for specific cases, small areas is a very good option. But tell a farmer that it will take 3 hours to fumigate a field when with the tractor it takes 30 minutes.........
Time is money, and in agriculture the same thing happens to farmers as to us with drones, we have to be looking at the sky all day long. Depending on the weather conditions you must run away in order to make flights on many occasions. Time is of the essence.