> A close relative is a practicing surgeon and a professor in his field. He watches youtube videos of surgeries practically every day.

A professor in the field can probably go "ok this video is bullshit" a couple minutes in if it's wrong. They can identify a bad surgeon, a dangerous technique, or an edge case that may not be covered.

You and I cannot. Basically, the same problem the general public has with phishing, but even more devastating potential consequences.