That whole story sounds a bit apocryphal but even if it's true this is some sort of semi-literate culture. If they're making marks in mud, how are they supposed

That whole story sounds a bit apocryphal but even if it's true this is some sort of semi-literate culture. If they're making marks in mud, how are they supposed to encode geographic positions with enough accuracy and write them to a computer system of any kind. And then have everyone understand and agree to what it means. Why it would it be superior to taking a picture and posting it to Whatsapp or Facebook?