Well, I want to propose an answer. But I must warn you that some questions do not fall into the proof of Western thinking. So, remember, this is just my opinion.
I have had excellent foot massages by trained Chinese practitioners. In the course of those treatments, I felt better. Nothing dramatic, but I definitely had more energy. The treatments were done by people who could seem to find places that hurt just a few millimeters apart. But once treated on a Monday, then the treatment two days later was much easier.
I want to propose an idea. It is that not all treatments can be evaluated best by a double blind, placebo controlled, crossover study. (Known as the Gold Standard)
I used to hear about appendicitis when I was a kid. In those days, when the appendix burst, it often spelled death. So when people had appendicitis, they were rushed into emergency surgery. All the people I knew who had the surgery got better or at least said that they did. But they did not participate in a Gold Standard study. All of them got surgery to remove the appendix. No one got surgery and had their colon removed instead or were just cut open and sewed back up again. And they all knew that they had surgery. And the doctors knew. To be true, according to the Gold Standard, a portion of them would have had a different surgery or just a cut and mess around with internal organs surgery. And the doctors would have had to be kept in the dark. But they were not allowed that Standard of medicine and somehow still survived to tell about it.
Of course, I am forcing the argument a bit here. Maybe even pushing it to the absurd. But I am trying to suggest that there are levels of truth in the observational practice of helping humans with health problems that may not fit the Gold Standard, but that are not false just because they don't fit. Most body treatments that deal with Traditional Chinese Medicine's meridians, like reflexology, have that problem.
On the chance that those who report help from reflexology are only better because of the placebo effect, I still don't doubt that they are feeling better. But that is just my opinion. And that is what you asked. Thanks for listening.