Not worth it for Miami.
They're building a good foundation with the defense and even if they got Deshaun Watson, he won't have any real offensive weapons to win every week. DeVante Parker is a decent, but not game-breaking player. And the rest of the pass catchers are mediocre at best.
The Dolphins would be asking too much of him. It also puts tremendous pressure on Brian Flores to win immediately.
Watson is a good player but Miami isn't the place for him.
The Dolphins should focus on strengthening the lines and getting skill players for Tua.