[quaddo]

"A picture is worth a thousand words" or some such.

That said, I've certainly heard that different people prefer different ways of learning/consuming knowledge. I myself will choose video for some things, illustrations/graphs/images for other things, and text/tables for yet others. I do have a fondness for well done images, though.

Even the style of text can have an impact. Bullet points for providing instructions, instead of a long paragraph of sprawling text.

Another thing I picked up some 15 years ago is borrowed from newspapers: the concept of "above the fold"; get the main points out there near the top, and keep it concise.

[AnimalMuppet]

A picture is worth a thousand words, but most instances of "a thousand words" cannot be expressed by a picture.

[quaddo]

Pictures/visuals just communicate differently.

A well-done graph can communicate data and the desired message quickly. At the opposite end of the spectrum, we have poorly done or deceptive graphs.

An illustrated magazine will communicate a story differently, compared to a text-only novel. There's nuance to each approach that the other can't quite capture.

A photograph or painting can elicit a different level (breadth, depth) of mood/emotion that words might merely hint at.

Of course, what's useful in one context could be pointless in another. An introduction to photography would do well to include some illustrations, whereas a book on meditation could probably do fine with few, if any, images. Another example is Gray's Anatomy, which would probably be more challenging to consume if there were no illustrations.

Some subjects such as learning a martial art can be helped by using pictures/illustrations, but realistically when used as the only source of knowledge fall short of adequately communicating proficiency in said martial art, where only in-person instruction would really suffice.