We do include illustrations, but in fairly defined categories: when they’re factually illustrative, when they’re graphs or charts, when they’re part of the plot (an illustration of a clue in a murder mystery, for example), or when they’re referenced from the text.

The last point is why the Beatrix Potter compilation I did ended up with illustrations: the text specifically references the illustrations in a couple of the books (“Can you see…?”) so they remained. It did mean writing 602 pieces of alt text though[1] so it was a fairly major undertaking to include them.

[1] https://standardebooks.org/ebooks/beatrix-potter/short-ficti...