Yes, it is expressive. You are bringing people to life, enhanced life, on stage, tv or film. A writer, very expressive too, creates a person, a place, a time on paper: why does this person (character) do this, feel this way and us (the actors) bring the depth to the person; who, before we interpret him or her and breathe life into the character, was words and description on pages in a script.
It is beautiful to spend an hour or two, relating to another human being, or several . . . creating another human being from within yourself and enhancing the audiences experience by sharing this person's emotions, angst, conflict and love, hatred and passion with them [the audience]. Whether you play a serial killer or the kindest person in the world, you, as an actor, must find his or her humanity. Because even the most evil person in the world doesn't feel he or she is evil; and everyone loves something or someone.
Being an actor teaches tolerance and understanding to an actor. We learn what motivates every type of person, we learn a bit of psychology, too. There is a beauty to wear another person's persona, to become something you are not, yet with a touch of you in them.
Actions (or, in this case) acting can speak as loud, if not louder than the words. Think of great films and stage plays which changed our world, even if for a moment or two: To Kill A Mockingbird; The Green Mile; The Sixth Sense; Casablanca; Schindler's List; The Miracle Worker; The Ten Commandments, West Side Story, The Heart Is A Lonely Hunter, Children Of A Lesser God, etc., etc.
Through acting, we can reach so many with messages of why prejudice kills (i.e. West Side Story, To Kill A Mockingbird, The Green Mile) or how anyone can overcome the biggest obstacles (The Miracle Worker, The Ten Commandments).
Actors have the priviledge to inspire, to move, to entertain and to express life, to bring to life and reach so many. We get to connect and find the acceptance, and oneness among us who live on this planet.
And on a less serious note, we get to "play" for a living. We don't have to really grow up! And there's nothing more fun than getting to pretend for a living. All children love to pretend. Us actors are big children, spending our lives pretending on the stage or sound stage. There's enough hours in the day where we have to be grown up's! Might as well play for a living!