Wow!!! That's pretty wild. 40K-75k words is 160-300 pages of notes according to standard words per page! Your entire campaign is ~1600 pages long! That is amazing bookkeeping. Do you publish this anywhere? I'd be interested to scroll through these campaign notes.
No. I'm too arrogant for that. Nothing I have is publishable or currently formatted to publishable quality, but I like it and just like the wild dream were for no reason whatsoever, someone picks me without any prior experience to work on the Dungeon & Dragon's cartoon reboot (my character introduction for Sheila and Bobby is fire if I could get shoplifting through the censors) there is this part of me that looks at my bounty hunter campaign and is like, "This would be better than The Mandalorian". Of course, I would absolutely blow the budget for a TV show, so there is that. One thing ttRPGs definitely do is big scale at low cost.
The last time I tried to turn my notes into something someone else could use and I wouldn't be embarrassed to show them it took me far for too long revising and filling out half-filled entries. That was the notes for running I3 Pyramid in 3.0e D&D, which ended up being more than twice the page count of the original adventure. As someone else noted, there is a huge difference in labor in getting 1000 words usable for yourself and usable for someone else. I got a post published by EnWorld at one point, and I absolutely was mortified that my stream of consciousness was going to be held up as anything to publish.
Your page counts are bit higher than what I actually have. 40K is about 80 pages IIRC (single spaced, usually 10 pt font but 9 pt for stat blocks). And of course, stat blocks are often redundant - storm troopers show up in multiple adventures, and I prefer to have a stat block right there in the encounter (though sometimes I consolidate into a "forces" entry with a description and stat blocks for what a faction has available when I can't know ahead of time necessarily when or where encounters will happen). But yeah, I have a lot of pages.
I was a player in a campaign in college that did have over 1600 pages of notes (my own character sheet ran around 80 pages front and back, once it listed all henchmen, retainers, hirelings, maps of buildings owned, libraries of books owned, ships that I owned and the stat blocks for the officers of the ships, etc.) and among other things the DM had seven sentence NPC entries for like 1000 named NPCs, and my most recent D&D campaign probably hit that level or because the "Player's Handbook" for that campaign was 600 pages in MS Word and there was probably 2 or 3 times as many adventure notes as I have for this Star Wars campaign.