I think you vastly underestimate the importance of fiction. Fiction may be the best canvas for creative and abstract thought, the place where possibility is explored and the 'what' and 'why' is established, without being mired in details. Before we invented things, we thought of things to invent, and in those moments we were writing fiction.

Technical writing is 'how', and that's being absolutely consumed by AI. When AIs can build anything, the question of what we should build and why is the most important.