Right, and it also prevents positive outcomes. People chronically lie to their doctors about their actual lifestyle behavior and then are surprised that the Dr. didn't catch all the warning signs for some disease.
Cameras won't add more data as they'll simply discourage people from admitting anything or even going to a doctor. I would not allow my doctor to film me, nor would I imagine most sensible and normal people who have an ordinary sense of privacy. Your doctor works for you, not the other way around, you decide what is acceptable behavior, not them.
More data = better outcomes.