A coworker got a German shepherd, insisting she grew up with the breed and knew how to train them and exercise them properly.
She went to a training class where she and her dog theoretically learned “heel”, coworker just didn’t listen. I had the dog on a leash, commanded “heel”, it came right over to my left, and coworker was baffled because she didn’t know her dog would do that.
If my coworker is at all representative of the average dog owner, it’s the owners that need the training.