17 years??
Are you writing a new War and Peace?
Hum, how can I explain this succinctly? XD
TLDR: The issue was never length; it was always density (of meaning) and style.
The full story :p
I started at first, with a French 3rd person past narration, basic stuff. My MC was flat emotionally as a board. She was basically a train you would hop on to visit the world, and it pissed me off as I was finishing the first draft. I also had no reach, reader-wise, writing in Canadian French in a province with barely 7 million people and no interest in the cyberpunk genre at the time.
Then, I started to experiment, first in English because 1 reach and 2 it was the language of the setting itself. Then I found out first person present was suiting the story style better, but I wanted to go further in exploring. I removed all narration and created a sentient brain implant to serve as a foil/counterpoint/present narrator for some aspects in the officially named V2, it was a wild style, using name tags to guide the reader a bit, and the text was exclusively dialogue and stream of consciousness on purpose. It forced me to make my character THE story, to give her depth emotionally. I couldn't cheat with a narrator telling us things... but it had a big downside. While I nearly finished book 1 (again), I realized more and more that this style didn't work with long action scenes. I could do some tricks to flesh out a bit a few dirty hits, a quick fight... but nothing sustained without it sounding unnatural, like a boxing match on the radio with commentators getting excited for the listener... it was not working.
So I restarted my tests, tweaking things, and practiced my English on the side (because you know... ESL)
From there, it took 7 years to find a working solution. Add sensory elements only as narration. It kept the visceral first person perspective and dialed it to eleven while giving me an outlet for what the MC is seeing, touching, tasting, smelling... so still a subjective perspective.
In parallel to this, I was reworking the meaning of the story. It has multiple concurrent lenses to analyze it from, stacked in "quantum superposition":
Some of the lenses:
Albert Camus' Absurd
Descartes: Cogito Ergo Sum
Plato's Cave Allegory
Cyber-Budhism
3 core symbolics: sakura, kintsugi, phoenix
a nuanced humanistic view on equality
A Gnostic allegory
A critique of late-stage capitalism/neo-feudal capitalism with potential solutions
Existentialism
Post-humanism
theory of mind
trauma therapy (specifically Complex PTSD)
The progression throughout the 7 moral development stages of Kohlberg
Maslow's hierarchy of needs.
AND it has a planned "6th Sense" like ending that transforms it from a gritty personal tale into, on a second reading, a philosophical sci-fi about the meaning of existence and, well, meaning itself.
You can read the story over and over and always find a new interpretative lens to see it from.
Am I rewriting War and Peace... no, I'm making my own crazy stuff.
Lately, I've been working with AI. I'm adding 1.3 songs per chapter, and once AI gets better for images to do what I want, I'll add a lot more images and refresh those I have (mostly place holders for now.) They are an integral part of the narration; my narration is the negative space in the conversation between image, sound and text.
All songs have been made for the story specifically and represent: propaganda, subconscious emotions and thoughts of a character, pov from secondary characters, diegetic cartoons, diegetic songs...
The images are the "one image is worth a thousand words" way to skip descriptions in the text. To clarify action scenes, to give the characters a face and so on...
Oh, and I also add a UI with pixel art for the brain implant directly in the text sometimes. (strict rules on that).
Finally, a big part of it was dealing with my own issues. I was writing about CPTSD to start with, and the more I healed, the better I could write the thing. I had better answers to offer, and ultimately, it changed the grand finale to something that... well, it will be epic and moving at the same time if I stick the landing.
I was actually telling people that AI is literally, by definition, 1 note. I don't mean that musically, I mean that as far as creativity.
If I asked an AI to write a chapter, it could do so quite effectively... but I am not a 1 note writer. Even my character's insults tend to be multifaceted. So, I could absolutely ask the AI to write my chapter, and then afterwards, I would have to completely rewrite it to give it depth. That is not an indictment; it is simply the recognition that humans have multithreaded linguistics that an AI could copy parts of, but can never produce.
However, if someone were to...say... tell an AI (In a much more complicated and balanced way) 'write a story about my character's childhood that would justify his attitude in this chapter' and then re-write that story to make it their own, then I doubt very much it would be either intrinsically 'less' or flawed compared to the rest of their text.
The thing is, writing is the HIGHEST art form. Every other art form can be easily mechanically reproduced, but writing requires communication, just the same way talking to another human cannot be reproduced. And no, I am not talking about that stupid test where people type into a console and try to figure out if it's a computer at the other end... I am talking about literally talking, with facial expressions, voice intonations, etc, we writers do that as a matter of course. Writing is an art form that cannot be artificially created, but it CAN be reproduced, like any other art form... but reproduction might seem like creation to other arts, it is most certainly NOT for writing.
I don't disagree that AI can get stuck on one note; I agree on that, but you might be surprised. Sometimes it comes up with really complex things on its own... It's a roll of the dice, really.
What I disagree with is that other arts can't be as complex as writing. Symbolic linguistics is present in many other forms of art; you simply have not been trained to interpret them fully if you don't see it. This is a bias you developed as someone who focuses on writing, I'm guessing.