Let's locally mass produce yarrow, boneset, and bugleweed! The problem is, you don't have to work for them.

Actually, though, here is the little shimmer of an argument: so many "modern" medicines are actually plant-based poisons-- colchicum, belladonna, yew, sweet clover (actually fungal), et cetera. And they have some very foolish flaws: they don't even use yarrow, or bugleweed, or any of the countless genuinely effective herbs, but instead try to replace some of them with substitutes that don't work nearly as well.