In my opinion, I would say the role of the writer in the twentieth century was a messenger to the people about what was happening in the world around them. The writer would come up with a story that was written to entertain but it's main purpose was to explain to the readers about government issues, political issues, and events that were taking place at that period of time or even past events that had already taken place.
In the short story, "Shooting an Elephant", the author, George Orwell, states "All this was perplexing and upsetting. For at that time I had already made up my mind that imperialism was an evil thing and the sooner I chucked up my job and got our of it the better. Theoretically-and secretly of course- I was all for the Burmese and all against their oppressors, the British." (Orwell, Shooting an Elephant) In this quotation, he is describing how he is for Burma and against the British Empire. "Shooting an Elephant" was George Orwell's attempt to explain his feelings of guilt about the British colonialism.
Also, authors in the twentieth century also wrote about their own personal experiences. " Heart of Darkness" by Joseph Conrad is derived from his voyage on the Congo. A quote from the story describes his journey up the river, "Going up that river was like travelling back to the earliest beginnings of the world, when vegetation rioted on the earth and the big trees were kings. An empty stream, a great silence, an impenetrable forest ; you lost your way on that river as you would in a desert, and butted all day long against shoals, trying to find the channel, till you thought yourself bewitched and cut off for ever from everything you had known once- somewhere- far away- in another existence perhaps." (Conrad, Heart of Darkness) Authors in the twentieth century poured their entire heart and soul into their writings. They wanted the readers to feel every little thing that was either going on in the world or the author's experience.