It seems possible to do better than average here? Just from reading this article, we learn about some "cancer" that is less scary than it sounds and unlikely to cause a problem.

I would be more skeptical if there were a study showing overtreatment still happens in a population informed and wary of overtreatment.

Right, micromotives. But what's best for me, personally, may be different than what is best for a whole population.

Medicine is individualized. If you have certain risk factors you may benefit from a particular screening tests or even prophylactic treatment and procedures. These should be evidence based too, however. Same when you're having symptoms.

The topic at hand is, as stated up-thread, "full body MRI scans for healthy people."