We only have writing and, consequently, people who's names we know a few thousand years back.
A cult figure before writing would have more limited reach, and be forgotten because their name wasn't written down. But they'd still have been a cult figure.
The Buddha lived before writing in India. We have plenty of other stories that were passed by oral tradition before they were written down.
It's an interesting hypothesis we can never prove. We don't even know how old names are.