a) Entertainment and arts are useful, even Stone Age hunters and gatherers left some art behind. It is part of our humanity. We obviously feel need to produce and consume art. (Maybe not you, but we the people in general.) And movies are art.
b) Big sets of people, like California is, need to be managed somehow. Individual politicians might be useless, but the office of the governor is useful.
I would question whether any of those count as useful.