but the Captain always decides.
I can't disagree with you really, because officially of course the Captain decides. But my view on leadership is a role that majors on responsibility and minors on authority. Although, the Captain is responsible for the decision, ideally it is a decision agreed by the crew. The Captain is responsible for ensuring decisions are effectively actioned in accordance with the aims and principles of CRM. A possible alternative is the Captian persuing a course of action differing with the FO's view, which would probably be an unhealthy state of affairs.