And much of the 20th century was characterized by a very similar progression - we had no clue what the actual mechanism of action was for hundreds of life saving drugs until relatively recently, and we still only have best guesses for many.

That doesn’t diminish the value that patients received in any way even though it would be more satisfying to make predictions and design something to interact in a way that exactly matches your theory.

We were using the compass for navigation for thousands of years, without any clue about what it was doing or why. Ofcourse lot of people got lost cause compasses are not perfect. And the same will happen here. Theory of Bounded Rationality applies.