I believe that if you invest in a feedback mechanism for improving the signal:noise ratio of writing, people are smart and will naturally gravitate to where signal:noise is the highest. If people in an org aren't reading, I generally take it as a signal that documentation is incomplete and misleading, or the signal:noise ratio is way too low.
In orgs where the muscle for long-form reading has atrophied (for the above reasons), you can try to write document to account for a weak long-form-reading muscle.
Begin your document with an abstract TLDR and ToC, open each top-level section with a TLDR paragraph, and provide pointers that imply the TLDR assertions are supported by evidence (i.e. internal links to the relevant section).
The key to good TLDR-writing is terse, in-order parsable sentences, and short paragraphs (one sentence, maybe two per paragraph), with tasteful font-weight choices. I'd discourage using font-weight outside of TLDR's, except maybe to highlight keywords.
I think wikipedia is a glowing example of what documentation should be. Some pages are huge (e.g. https://en.wikipedia.org/wiki/World_War_II), but each section is dense, and filled with links to more detailed pages. To find the specific answer to some question, you often only need to navigate the table of contents and two or three sections/links. And yet, the pages can also be read straight-through. Writing like this is a hard skill to earn, but it's reward is probably a culture of reading.