Phase 3 trial, not just any study. The results are required by FDA in order to approve the vaccine.

Nobody else is going to back such a study. So that's going to be true for every drug.

Indeed. And pharmaceutical companies will never do studies for medicines they cannot patent. And you can't patent natural medicines, only synthetic. So only the synthetic ones that are created by them are being studied and are the only "proven" medicine.

Convenient not?

Maybe we should have an independent institute backed by citizens, that does these studies, for both natural and synthetic medicines.

But that would destroy the pharmaceutical industry.

We do have a small one, The National Center for Complementary and Integrative Health.

It does a bunch of studies like the ones you suggest, but hasn't yet discovered any blockbuster results.