If you agree that a system in constantly in flux and then freeze the current best practices, then you should not be surprised when the system has changed enough to where there are new best practices. The problem is the degree to which the current best practices are frozen. When it comes to the delivery of health care, this freeze comes from tactics such as regulation, certificates of need, credentialing, education requirements, and limited medical school admissions. Think those are easy to change?
I imagine a future where division of labor leads to specialization and greater efficiency:
You suspect an injury or illness and contact a Care Coordinator (CC). The CC sets you up with a Diagnostic Specialist (DS), who is steeped in symptom recognition, testing, and decision-tree diagnosing. The DS diagnoses a kidney stone and creates a treatment plan for you.
The CC sets you up an appointment at the "hospital" with the kidney stone specialist, who treats and was trained on only this family of problems. The CC later follows up with you to ensure you are satisfied. If an emergency happened during the treatment, an Emergency Specialist (ES) would be alerted to stabilize you.
This scenario is over-simplified of course, but it illustrates how specialization creates experts. These specialists/experts do not need to have gone to college for a decade either. Do you care whether your cataract specialist missed classes that discussed knee anatomy? Do you want to pay extra for a podiatry specialist that is knowledgeable on the reproductive system?
Earlier doctors had to be generalists. Today's specialists are really generalists AND specialists. Reminds me of what Mitt Romney said about how he wanted to go to business school while his father wanted him to go to law school: he compromised and went to both.
In this scenario, training would be radically shorter but radically more focused. Many more people would be qualified to be a specialist. So you would have higher quality (more experts), a larger labor force, and lower cost (wasteful college and training time). This is not to say that there is no place for generalists (a DS would need massive training), just that not everyone needs to be one.
Too bad the medical profession froze its best practices. At least it waited until after the era of phrenology and leeches.