Main point: Insurance companies only have you for a couple years, so it’s not in their immediate self-interest to prevent you from getting cancer in 5 years.
I heard a statistic mentioned during an interview with Dr. Peter Beilenson that the average duration that a person holds an insurance plan in the United States is just 2 years. In other words, an insurance company (acting presumably in its blind self-interest) has no incentive to cover care that is preventative.
So what if a checkup or scan or consultation with a dietician could help reduce the risk of cancer in 10 years? Covering that checkup, scan, or consultation costs the insurance company money, without resulting in any savings, since the patient will be off its plan in all likelihood if they do get cancer.
Of course, this is a very common problem that game theory addresses. In this case, insurance companies need to cooperate to maximize profit and minimize cost. Businesses are rarely good at cooperating in that way however. That, in theory, is the role of government: to “encourage” or downright force cooperation through regulation.
I’m obviously not a healthcare policy wonk, but it seems to me that healthcare should be much more proactive and not just fall back to being “sickcare”.