written language came about long after cities and industry and all that. it was the development of agriculture, that freed up time to create more interesting things (initially with clay) and then the wheel (to carry more stuff around) that led to the need to keep track of the massive hoards that local warlords (i.e. 'heroes') were collecting from the subjugated masses. our first written documents were lists of things kept in treasuries and trade lists between cultures.

so you have it backward but the point might still be valid.