It's not just docs too, it seems to be some general phenomenon that users don't read most anything on screen.

This is from almost 20 years ago [0] and the original stretches back almost 30 years now [1].

[0] https://www.nngroup.com/articles/how-little-do-users-read/

[1] https://www.nngroup.com/articles/how-users-read-on-the-web/