Oh well, there goes potentially thousands of years worth of medical knowledge, linguistic insight, etc.
If that can somewhat reassure you, most of the "traditional medicines" once tested in proper clinical trials, are just about the same as placebo. I'm not saying all, but a good majority. And people used to die from simple infections way more before we had modern medicine with antibiotics and the like, so I'd rather count on modern medicine any day for discoveries and treatments.
Staying in the jungle for a few thousand years leads you to optimize locally sourced flora and fauna to amazing levels to solve a range of medical conditions. That could be helpful to a lot of people in many social and financial conditions.
Do you have a source to back that up?
The only exception is diabetes, because that's easy to spot by looking for sugar in urine.
We weren't always taking asthma inhalers from Walgreen for the several thousands of years of our existence on this planet.
You seem to asking for proof that humans for all these thousands of years of existence pre industrial revolution needed some kind of a health care system to survive.
There are some things that go as an axiom.