> Graphical symbolic communication is tens of thousands of years older than what the article discusses.
This article says that the earliest proto-writing is 10,000 years old - 3-d clay counters used for accounting. What was earlier?
https://sites.utexas.edu/dsb/tokens/the-evolution-of-writing...
Proto-writing is still quite far along on the spectrum I'm talking about of contextually defined symbols. Lascaux and chauvet have plenty of examples generally agreed to be partially symbolic, just off the top of my head.