Also most of those local didn't even have a writing system in the first place. I'm not sure papyrus is really that important, clay tablets worked fine in earlie

Also most of those local didn't even have a writing system in the first place. I'm not sure papyrus is really that important, clay tablets worked fine in earlier periods and parchment was superior to it in most senses besides much higher cost. Had the Romans switched to parchment several centuries earlier we'd probably know way more about them. Also whoever hold Egypt in the past: the Egyptians themselves, Persians, the Macedonians technically monopolized the papyrus trade. Nevertheless the trade still went on, that simply how ancients economies worked. I think a bigger factor is that due to over-harvesting the plant used to make papyrus it became much more expensive as time went on making parchment much more competitive.