The writing advice is to write with a reader in mind. The assumption is that the writer thinks up an audience before starting to write, so they are telling to story to someone specific. As the writer puts words on page, they are telling the story to this imaginary audience sitting across the desk from them. One author was using voice to text software and using it as part of his writing process to the point of not wanting to upgrade for fear the voice would change causing his audience to change.
When I write I don’t write to a specific audience, because I am just a channel for the character to tell me the story. I become the reader who I am writing for. The story is one I want to read, though at times the character goes off to places I am not sure about it. Usually by the time I reach the end of the story, I understand why they went where they did and it works for the story.
There are some of my stories where my only reason for writing it down was for my own entertainment. My western, Chenarcor, was me following the characters around and writing down what they did for my own enjoyment. Turns out that other people have enjoyed it as well, so it seems to be a good way for me to write. Other people do need that audience they are talking to when they write, which is okay as no one way works for everyone.