Science is slow in general and medical science mostly examines population-wide efficacy rather than individual efficacy, as its these population-wide conclusions that help form guidance for practicioners serving a population.

For any given potential treatment or remedy, an individual may be an outlier whose specific attributes weren't represented or analyzed in that kind of research or whose response would have fallen into the noise floor.

You can certainly choose to only accept those population-scale conclusions, but many of us only have so many decades to try to sort ourselves out.

And further, because of the feedback loop between thought and many autonomic processes in the body, one can even experience real remedy from formally invalid treatments. For an individual, that's all you need.