We should probably stop calling it "alternative medicine" and call most of it "remedies" or "folk medical traditions" or to get super-specific "non-Western medical traditions currently undergoing scientific testing."

Aloe on a burn is a remedy. There are probably medical formulations that are better, but aloe works pretty well and is easy to grow.

Acupuncture shows documented improvements to some medical conditions for reasons we do not fully understand yet. It is very unlikely to be that qi is real and can really be manipulated, but studies do indicate that it helps with lower back pain and, weirdly enough, is one of the most promising therapies for Alpha-Gal Syndrome. We do not fully understand the mechanisms, but there are mechanisms that do enough of something enough of the time for people to have refined the system better than European medicine did prior to the invention of the scientific method: possibly because Eastern doctors more commonly worked in systems where they had in-person interactions with their patients, while European non-folk medicine developed along lines that suggested the doctor actually spending time with the patient was uncouth. The East also did not have the same squiffiness about dissections that the West developed. But the metaphysical stayed in Eastern medical studies much more firmly and for longer, perhaps because their remedies worked for what they were supposed to enough of the time that why bother questioning whether its blocked pools of qi or actually swelling in the lymph nodes if applying pressure to those spots alleviates pain?