As another Emacs user it'll remain immensely funny to me how Emacs can be shoe-horned into almost any conversation. Probably due to the fact that even when it's not the best tool for the job, by any stretch, it can be kludged into something useful enough.

And yeah, regarding writing (fiction and non-fiction) there's Emacs Writing Studio which people praise and I haven't personally used: https://github.com/pprevos/emacs-writing-studio

There's also some packages like Olivetti or Writeroom-mode for just a "Zen mode" writing experience.