The 3500 BCE date for horse ridding is speculative and poorly supported by evidence. I thought the language in the bit I pasted made that clear. "Horse being driven" means attached to chariots, not ridden.

Unless you want to date the industrial revolution to 30 BCE when Vitruvius described the aeolipile, we can talk about the evidence of these technologies impact in society. For chariots that would be 1700 BCE and horseback riding well into iron age ~1000 BCE.