It's very difficult to effectively use some natural remedies at scale for a variety of reasons:

(1) They have a large number of active ingredients that are not cost effective to manufacture synthetically or isolate

(2) They have an active ingredient that is not yet possible to manufacture synthetically or isolate

(3) The active ingredient(s) are not shelf stable once isolated from the parent product

Lastly, and most importantly, natural remedies are not patentable. This means there is not enough money to get them approved for marketing as a cure for disease.