>>39125543That's not quite right: We have a single example of Epi-Olmec (basically the term for Olmec-area cultural sites from later into mesoamerican history then the main early few Olmec ones) writing from 900BC. Granted, we have no idea what the fuck it says, but it exists.
If you wanna go full autism part of the problem is that "Olmec" isn't even really an actual culture, per say: It's more just a artistic trend we see throughout Mesoamerica, especially around the Gulf Coast area, around that time period, and the earliest sites demonstrating complex society, monumental archtecture, etc in the region happen to have those artistic styles and traits.
Anyways, here's a quick tl;dr crash course on the timeline of Mesoamerican history from the Olmec to the Aztec since most people probably know jack shit about it because schools don't teach any of it.