Making a request to one documentation topic often requires the technical writer to adjust other topics as well.
When a new feature is added to a software product, there may be multiple guides that need to be updated. First document needing updating could be the product’s user-manual. Second document could be release notes. Both these documents are made available to users of the product. Third could be code samples.
Changing one topic can set off a cascade of other needed edits across the entire documentation set.
In summary, a technical writer must grasp the product as a whole to be able to integrate the new information into a larger documentation set.
Therefore it’s not just an ability to write that matters. It’s also the ability to integrate information into a larger, coherent whole that makes the role of technical writing unique, valuable, and challenging.