I strongly suspect the truth is both are "right", but they're both optimized answers to slightly different problems.
Mainstream medicine is hyper optimized for the most common 80% of cases. At a glance it makes sense: optimize for the common case. Theres some flaws in this logic though - the most common 80% also conveniently overlaps heavily with the easiest 80%. If most of the problems in that 80% solve themselves, then what actual value is provided by a medical system hyper focused on solving non-problems? The real value from the medical system isnt telling people "it's probably just a flu, let's just give it a few days and see" it's providing a diagnosis for a difficult to identify condition.
So if your question is "how do we maximize value and profit in aggregate for providing medical care to large groups of people", mainstream medicine is maybe a good answer.
But if your question is "how do we provide the best care to individual patients" then mainstream medicine has significant problems.
Part of providing good care is not burdening the patient with tests or treatments that are very unlikely to yield benefit. Put another way, the mission of healthcare is not "health at any cost."
The mission of healthcare in the eyes of those who provide it, isn't "health at any cost".
For the people on the other side, "health at any cost" is pretty much the goal, usually limited by the "cost" side of things, especially in the parts of the world where they haven't yet figured out the whole "healthcare for the public" thing.
Cost here doesn't just include financial cost, but also time. As an extreme example, you could surely catch diseases earlier by visiting a doctor for an hour or two every day - getting tests for all sorts of things you might have conceivably developed. But that would make your life worse, and so most people wouldn't do that even if it was free.
Mainstream medicine is hyper optimized for the most common 80% of cases. At a glance it makes sense: optimize for the common case. Theres some flaws in this logic though - the most common 80% also conveniently overlaps heavily with the easiest 80%. If most of the problems in that 80% solve themselves, then what actual value is provided by a medical system hyper focused on solving non-problems? The real value from the medical system isnt telling people "it's probably just a flu, let's just give it a few days and see" it's providing a diagnosis for a difficult to identify condition.
So if your question is "how do we maximize value and profit in aggregate for providing medical care to large groups of people", mainstream medicine is maybe a good answer.
But if your question is "how do we provide the best care to individual patients" then mainstream medicine has significant problems.