I watched a movie from the novel "I Will Find You" by Harlan Coben. There is a scene where a woman who's a journalist is reviewing and marking up a guy's planned speech. He comments on how many changes she's making. Her response is:
"Writing is re-writing."
I thought that is so true.
AI would agree with you - to it, writing is rewriting someone else's words.
That's not what the character (author) meant.
Write your first draft quickly, and then roll up your sleeves and really write the novel during the re-write. During the re-write, choose the best word. The best sentence structure. Tune dialogue. Move stuff around. Add stuff. Delete stuff. Look at the pace. The consistency. Do all the stuff that makes a novel great.
I spend the majority of my time writing a story/novel during that phase. Some call it editing, but it's much more than correcting typos and grammar errors.