There are many loopholes in every website that are difficult for novices to pick up but professional technical writer services are experts at picking them up:
Another staff produces documentation "on the side" due to a lack of resources dedicated to content writing.
Engineers and content creators don't communicate well.
There is a lack of focus on determining what clients require.
It is inefficient and painful to write and publish.
The content is never updated, it's disorganized, and it's inconsistent.