First you plan the piece in your head. Then you write it out.
But it falls flat.
When you work in that order—plan first, write second—you're doing the one job that AI already does better than you: assembling what you already know.
Experts work in the opposite order: they write to find out what they think, then they rebuild that idea in the mind of their reader.
Readers don't read in the same patterns that experts use to write. So after writing-to-think, experts need to chart a new course for a reader.