We absolutely judge books by their covers.
And we judge text by its format, even before reading a word.
Giant block paragraphs tell one story about what’s coming. Clipped sentences another. And micro-paragraphs, bullets, and numbered lists still others.
And all that’s before we get into typeface and formatting.
Getting the right words on the page is important. Structuring the page so that the right words will be read helps show that the words are in fact worth reading.