I am not saying they don't work, just normally not necessary.
Mo that's like saying decoys are not necessary for duck hunting. You can take passing shots, or decoy them. That's half the fun decoying the birds, making them land where they were not planning on landing.
One of the best dove hunts me and my son had, we set up in a field, all dirt plowed field no food. no other hunters in the field, dove flew over, saw our mojos, they would turn, cup up like ducks I kid you not, and come in from way up high. We had a 2 man limit in no time. It was the coolest hunt ever .