Kind of a shower thought, and maybe it’s just how I run campaigns, but it feels like there’s a lot of parallels between DMing and that guy who has a great idea for a book/movie but will never write a single page.
The DM comes up with “So what if there’s this guy with this magic power, and the only way to beat him is through a very specific process.” And then all the Players decide: who are the characters? What do they do? What do they say? How’s it all work out?
It’s not just you, but it’s also not most DMs. TTRPGs are collaborative storytelling. Books are single-author and have a consistent plot (generally, anyway).