It depends on your perspective.
From a cost efficiency concern, they aren't very effective - the number of issues that they come up with aren't worth the cost. My physical today covered blood (including PSA), urine, chest xray, height, weight, multi-lead EKG, and I did the colonoscopy thing last summer. Included with a good interview to assess other risk factors.
What other tests do you think a healthy 43-year-old athlete who eats a good diet needs? I don't need to be tested for things like metabolic syndrome, malaria, or most of the other things that executive physicals test. And I'd rather skip the radiation from the full-body scan, thank you.