Well, there's also the fact that the best doctors are the most in demand, so a doctor who isn't busy isn't that in demand, which is a good indicator that he isn't the best.
and of course we all feel comfortable being helped by "the best" doctor after they had a triple 16-hour shift.
It's quite crazy how hard medical professionals are overworked. It's impossible there's not plenty of mistakes happening. Whether you'll ever hear it is something different.