This is a fascinating discussion.
I am not picking on you, I promise, but
@curious_george what's the value of modern medicine? As individuals, being agents of our own health and well-being, what's the value in taking a risk in seeking care for any particular medical condition? The stakes are ultimately simple - life or death. Pain and pleasure play parts but you can have neither without...you know...living.
In aggregate, we can say with reasonable confidence that certain medications and certain lifestyle choices will lead to certain outcomes for some or many or even all people. But in small populations, those assumptions can start to fall apart and the statistical tails can suddenly have a meaningful outcome on only metric that really matters.
Perhaps I'm one of those rare ones that has an allergy to some or most pain relievers, and can't seek traditional medical care because I can't be properly numbed. And perhaps I visit the cancer-curing shaman who is able to address many of my issues in a way that modern medicine cannot. Should I discount the healthcare system and advocate for the woo-dude?
Suppose I do have cancer and I have the aforementioned condition, and I visit the woo-dude, and he's unable to cure my cancer and I die in 6 months. As I'm dying, should I continue to tell others that modern medicine isn't effective?
Suppose I notice that the 5 others whose cancer was cured by woo-dude saw those effects in under one month and after 6 weeks I seek medical care and although i experience great pain I am eventually cured - how am I to feel about the field then? What should I tell the woo-dude? Would he accept my response?
To
@Malcat 's point, upthread, why did I choose to seek care from woo-dude? I saw that his approach had measured success and although I had no clue whether it would work for me, it was the better alternative in my view. But then why would I seek Western medical care after no success from woo-dude? I personally would make that choice based on the evidence presented. I accepted that the woo-dude might have something up his sleeve that we haven't yet understood but then after seeing that it didn't work, I decided to turn to a system with known outcome and known drawbacks.
Because much of science, and medicine glaringly so, relies on our ability to trust others' reasonings and conclusions we have to as individuals determine where our confidence is to be placed. Note that faith /= trust as I describe it. The 5 people who visited woo-dude did so because they had less trust in the outcomes of the alternative system (Western medicine) and their trust was rewarded.
But why did they choose woo-dude? Did they happen to embark on a spiritual journey and stumble across an ancient temple where he was practicing spiritual healing? Or was he operating out of a former strip mall tobacco shop and advertising his services in the local paper? The latter being more likely, his aim was to deny Western medicine to a certain degree. Perhaps he viewed his practice as synergistic or perhaps it was antagonistic. But in either case, for the first patient he cured, he was able to turn distrust of one system into blind faith of another.
As with anything modern society has created, we build trust by demonstrating through evidence that something is beneficial to us as individuals. You have learned to trust your grandfather's way of life because you have evidence that through a combination of lifestyle and genetics you may be able to follow in his footsteps. Although your sample size is 1, in your observation, it has a 100% success rate and you have no evidence of the downsides.
But suppose I with an intolerance for painkillers find that your family practice involves the occasional Advil, and I follow the practice blindly only to die from an allergic reaction. Now your success rate drops to 50%. Do you still trust that this approach will be successful? Maybe a third individual succumbs again while following his lifestyle as best they can and now there is only a 33% success rate. Do you keep on going?
Conversely you share your grandfather's success with others and find that through careful practice each is able to outlast his expected lifespan and makes it well past 100. Now you have strong evidence that it works, at least based on your sample population. Does that enshrine his lifestyle into a medical SOP?
Again to Malcat's point, i can accept that your grandfather's lifestyle guidebook is successful but without evidence of why, I can also choose not to trust it.
Science and modern medicine confer the benefit of being able empirically demonstrate the reasons why we expect something to have a particular outcome. Either through chemistry/physics or through evidence based studies, we can prove or disprove to the best of our ability why an outcome occurred the way it did.
The disturbing and unfortunate truth that you point out is that not all scientific experiments are successful, and those which are or are not confer a benefit to society at the expense or success of the individual and the outcome of their own life.
To me, the biggest difference between the scientific method and commensurate alternatives is that the alternatives often back up their observations with "because I said it does" or "I haven't seen it fail yet". My chiropractor peddles a bunch of bullshit in the same way that ICP views magnets ("fuckin magnets, how do they work?") - there's no reason to believe that something doesn't work if it hasn't failed a very specific set of observations in a very specific population of people. But I still see my chiropractor because there is evidence that his services can help to mitigate the effects of my minor but frustrating scoliosis.
ETA - the thing about us
Sapiens is that we don't like to lose things, and we have a very very poor base-level understanding of probabilities. We have to force our minds to overcome the gut feeling that something which is statistically in our favor is something we should choose when our gut feelings tell us to run away.
If you knew that they outcome of a particular medical intervention were 66% favorable, 10% neutral, and 24% unfavorable, would you seek that care?
What about another practice which had a 10% fatality rate and a 70% success rate?
If woo-doctor has no statistics, but seeking his care would put you past the window of the 10% fatality rate example, and turn that same practice into a 50% fatality rate, would you still pursue the woo-dude?
What if the woo-dude has a 33% success rate and no adverse outcome, but in seeking his care the above were true (50% death rate because you waited)?
What about 50% success with woo-dude but if he fails, you're past the point at which modern medicine is helpful?
When does trust turn into faith?