Backing the currency of images with a word standard is pretty unworkable anyway. You can't trade a photograph for a thousand words in any marketplace I know of. And why would you?
The word is all that separates "prehistoric" from "historic". It is the prime accelerator of civilization's events.
Although the word is an incredibly advanced and enduring bit of technology, it works seamlessly at very primitive levels. Words can be carried around in a head, unarranged, then processed with a pencil and paper or even more basic, just say the words out loud. Talk is the wireless transmission mode for words.
Pictures have an unarguable force and immediacy. We do a lot of our thinking in pictures. But our emotional response to a picture is drawn not from our experience of life, but how we've defined it, and that constantly amended reality comes about mostly from the words we exchange with others.
Words make it possible to communicate across the ages and to aggregate understanding. A good thing too because, beliefs aside, we all started this life with no idea how we got here.
I've spent many years exploring the Southern California and Nevada deserts and the petrogylphs of the Paiute and Shoshone tribes who lived there for thousands of years and died out, I think, about 800 years ago. They never developed the concept of a written language, and now almost nothing is known about their lives and their culture. They lived for thousands of years in a circle of harsh sand, never knowing an arable, affluent environment was only a few hundred miles away.
But they sure left a lot of pictures behind.