More specifically, the ability to record ideas.

It's one thing to simply communicate, but to be able to record ideas and effectively enable cross-generational communication is extremely powerful. Native Americans, for example, had verbal communication and some limited written communication, but much of their knowledge has been long lost because it was passed down verbally. Of course, the United States did a good job at erasing their history by exterminating the native people, but you can still look to the Aztec civilization as a contrast in how recording ideas had an impact in how much we understand about their history.