A letter carries significantly more information than a pixel. One word can change the meaning of the rest of the text. (“joke:”)
I don’t think images have the same property.
But, I'd like to see someone try to communicate the Bhagavad Gita or the history of F=ma in visuals using the same amount of bits as text.
We forgot this about language by about the time of the Enlightenment era, when the intellectuals of the time thought that forcing everything to inhabit the structures of language (i.e., "rationality") represented the highest moral good one could achieve.
Text however if it is only a single word out, the whole meaning and readability can change. It needs a significantly larger data set to ensure clearer readability.
Just a shot from the hip response on this one.
And pictures aren't necessarily made of pixels. They are modelled as a collection waves (JPEG), and displayed as pixels. I don't know how LLM/whatever image models represent images, though.
Images are more global: changing the color pallette changes the tone (ha!) like a descriptive word in text.