I don't worry (yet) that LLMs can produce better docs than I can. A big part of my role is speaking to people to understand what users need to learn, then designing an organization for documentation around that. Writing is of course a big part, but understanding what to write and what not to write is often even more important.
Instead, I worry about a situation like the one in this post, where some exec thinks that AI can get you XX% of the way there for much less money. I think they would be mistaken, but what hurts my case is that it's inherently extremely difficult to demonstrate the value of technical writers quantitatively.