Just because you have a plot, doesn’t mean you have a story.
The first novel I ever wrote was all about the plot. This happened, and then that happened, and I explained how these awesome (I thought) characters discovered this cool mystery about the history behind my fantasy world.
It was terrible.
The writing wasn’t half bad, and the idea itself was pretty cool (to me), but there was no story to speak of. My characters followed a predetermined path that explained how a situation came to pass. The surprises and twists came not from what my protagonist did, but only when I decided as the author to finally reveal a piece of information.
This was not a book anyone else wanted to read.