You’ve kinda/sorta finished your book/first draft/whachamacallit.
In drastic cases, it could even be an outline that’s gone off the rails and landed in a ditch.
But.
Your original brilliant idea is drowning in a sea of ugly clutter.
There are dust bunnies in the corners.
An overflowing laundry hamper in the hall.
First chapter is suffering from ring-around-the-collar.
Inciting incident is ho-hum and forgettable (even by you).
Plot has more holes than plot.
Characters have mutated into unrecognizable forms (and you’re not writing sci-fi or alien invasion fiction).
Verbs are passive, the nouns flabby and adjectives rust in the front yard.
Ending limps to a conclusion.
You’re asking yourself: Did I write that?