The Tralfamodorians could be called Billy's fantasy formation. They allow him to become unstuck in time and revisit his past and future. This relieves him of the anxiety caused by his present life. Television programming is fantasy formation on a huge scale. Conflicts tie up neatly at the end of the show - they do not drag on for days or weeks or years as they can in real life, for example, a long standing argument with a family member.
Human beings have an inclination to avoid pain, be it physical or mental.
As people want to feel good, safe and happy, they will seek out anything relieves pain. They have no feelings of humanity whatsoever and are obsessed with killing. Even Roland Weary - he is armed to the teeth with his soldier's bible and three sided dagger. Killing and torture are all he thinks about, and in his final action, he makes Paul Lazarro promise to avenge his death by killing Billy. To escape his present situation of middle-class blandness and mental problems, Billy Pilgrim thrives in his fantasy formation of the Tralfamadorians, who relieve his anxieties about life and death.