The Inca didn’t “lack writing.”
They used khipu.
This was knotted, color-coded fiber cords engineered to record census counts, labor obligations (mit’a), storehouse inventories, tribute flows, and administrative data across thousands of miles of empire.
Position, knot type, cord hierarchy, and color all carried meaning. Decimal accounting. Layered structure. Trained specialists who could read and audit them.
Thousands survive.
An empire of millions ran on portable data architecture… without paper, without ink.
Literacy doesn’t have to look like a page.