There is a lot of knowledge in science and a lot of knowledge that is historical or traditional. The problem is that (almost) all the low handling fruit have been picked and there is a lot of intersection. To use a silly example, "drink water when you are thirsty" is science, historical or traditional knowledge? Curare is poisonous? Use heat to melt cooper? A lot of historical or traditional knowledge has been absorbed in science, in particular many medicinal plants have been confirmed and there are now artificial procedures to produce the same active component or some improved version.

So most of the things that are usually called "historical and traditional knowledge" are in the difference, i.e. things that have not been confirmed in a scientific acceptable way, or that have been debunked. So most of the leftovers are wrong or are very difficult to test (or both, wrong and difficult).

Just imagine the 20th season of MythBuster. In the fist seasons they pick popular myths and "confirmed" or "busted" them. Then they run out of popular myths and had to pick more obscure myth, and then crazy or weird ideas. They run out of authentic myths and started reproduce scenes in movies or to create their own myths. I enjoyed the show, but it's difficult to imagine what could they do in the 20th season.

The current state of science is similar. Most of the good parts of the historical and traditional knowledge has been assimilated and extended. The current questions are weird. (Is the neutrino it's own antiparticle?) The leftovers of historical and traditional knowledge are wrong or are very difficult to test (or both, wrong and difficult).