The problem is that many "traditional" remedies/drugs such as those found in Ayurvedic and traditional Chinese medicine have the "this must work based on a priori magical/philosophical knowledge, so no amount of evidence that it kills patients / does nothing at all will convince us to stop" problem.
There very likely are traditional remedies that absolutely do work, but those lie more in folk remedies (especially use of native plants in teas), which tend to be slow trial-and-error over generations, rather than formal systems based on magical principles.
There very likely are traditional remedies that absolutely do work, but those lie more in folk remedies (especially use of native plants in teas), which tend to be slow trial-and-error over generations, rather than formal systems based on magical principles.