I've used vim as a prose editor in addition to a code editor for a long time.

For me, Goyo was the plugin that always matched what I wanted vim to become when I was in "prose writing mode."

https://github.com/junegunn/goyo.vim

I combine with limelight.vim:

https://github.com/junegunn/limelight.vim

This partially simulates the experience/UX of the product iA Writer on macOS or iPad, which is my favorite prose editor, but is proprietary software and doesn't work on Linux.

As others mentioned, when in prose writing mode you can also flip on a handful of vim options, I save these as hotkeys in my vimrc. For example, spell checking and line wrapping.

In case you're curious:

https://github.com/amontalenti/home/blob/master/.vimrc

I played with some of these tools 12 years ago and created "dim", but it was really just Vim with limelight and goyo in a Docker container.

https://github.com/amouat/dim

There is something nice about having the editor as a separate command especially for writing.

I just checked these out and Limelight feels wonderful when editing and reading prose in Vim! I will definitely be using this in the future - especially when writing things for my blog.