Would you happen to know if the tribes in southern Venezuela are pretty much unaffected? Some of them seem to be living as people have been living for thousands of years, rather disconnected from the modern world.
It seems as though even those tribes have been prizing western technology, like fishhooks, shotguns, and machetes. Those are valuable trade goods.
Maybe they've sort of forgotten in the past few generations how to get by without those tools? Living in a jungle is hard as hell, and a machete and a shotgun sure do make a big difference.