Simple and Clean
Vonnegut's style is simple and plain. It's journalistic, even, in the quick, concise way it gets the facts of the story to us at about a fourth-grade reading level. This sparse style emphasizes just how sparse the 2081 lifestyle is. It's a life without flourish, without beauty. George and Hazel are watching TV and "on the television screen were ballerinas" (5). That's the whole sentence right there; fill in the details yourself.
The only time Vonnegut gets a little wild with the thesaurus is when Harrison and his Empress take to the sky. "They reeled, whirled, swiveled, flounced, capered, gamboled, and spun" (73). Ah, there's the flourish and beauty that is missing from 2081 life. It's only possible to live like that when not smothered by hundreds of rules.