I was rereading Stephen King’s On Writing recently (great book, by the way) and came across this quote from the “On Writing” section, Chapter 6, page 176 of the 10th anniversary edition:
It’s also important to remember it’s not about the setting, anyway—it’s about the story, and it’s always about the story. (emphasis in the original)
In context, King was talking about describing setting, but I think it is a useful reminder for we worldbuilding speculative fiction writers, who can sometimes get so caught up in creating our fictional worlds that we never get around to writing the story that inspired the world.
In particular, the last line — “It’s always about the story” — reflects one of my own deep beliefs about writing, which is that the writer should always focus on what will help the story first and foremost and worry about anything else second.