@mhoye All true, but there are some positive examples. On the corporate side, IBM has always been very good about producing complete, accurate, and up-to-date documentation tailored for different audiences - business, end users, technical. In the OSS world, I've found Arch Linux docs to be quite useful. But not everyone takes a professional approach to documentation, unfortunately.
@mhoye FWIW, on the Cobol Check project we've always treated documentation as a first-class citizen. https://github.com/openmainframeproject/cobol-check/wiki