The ability to communicate is not merely the ability to string words together coherently. It is the ability to authentically connect with people.
If you are in charge of an organization you may have the ability to tell people what to do, but you will never have the ability to tell them what to think. Great leaders do. They win over followers on the strength of what they say and how they act, and that is why the sincerity of communication is so critical.
Good leaders understand that public leadership is public theater, and rather than shy from it, they embrace it — authentically. And so, too, do their followers.