I am imaging you in the Amazon meeting a previously uncontacted tribe and asking, "How could you eat today if you didnt feel like hunting and gathering?" When the elders answer "we dont know" you would go back to the lab and try to invent Cheerios.
Just because people dont know about something doesnt mean that it doesnt exist. Just because something exists doesnt mean that one shouldnt work solving the same problem.
Not sure what your point is here, but I'd reinforce that in your Amazon example that would be perfectly good justification to create a food product directed towards Amazonians (or perhaps just a Cheerios distribution network in the Amazon?).
Just because people dont know about something doesnt mean that it doesnt exist. Just because something exists doesnt mean that one shouldnt work solving the same problem.