According to the essay "Why I Write," what are the reasons that one must write for the sake of themselves and society?

George Orwell is one of the most influential writers of the twentieth century. His novels, novellas, essays, and journalistic output have inspired countless writers who came after him. His essay "Why I Write" is a favorite among aspiring writers. The essay not only articulates Orwell's genesis and motivations as a writer, it also serves as a guide for those wanting to use the literary arts for social change and political expression.
Orwell is famous for his criticisms of the British Empire's imperialist foreign affairs ("Shooting an Elephant"). He is also an observant critic of government control (1984 and Animal Farm) and outdated social structures (Keep the Aspidistra Flying).
In "Why I Write," Orwell states that he is left with "facing unpleasant facts." In the essay "Shooting an Elephant," Orwell tells the story of being an officer in Burma and how he had to deal with the unpleasant facts of being part of an imperial government. These types of experiences helped him develop his writing style and inspired the recurring topics in his later works.
Orwell suggests that writing and social commentary cannot be divorced and concludes that an author writes out of a primal need. As humans, we react to external stimuli and experiences, and writing is a medium in which to articulate those experiences. It is similar to a feedback loop on a circuit board. An input, such as experiencing the authoritarian oppression of government, will eventually lead to an output, which in Orwell's case is writing.
Orwell also talks about the revolutionary nature of writing. As a journalist himself, he opines that journalists of his time are concerned by the greater matters of politics, social issues, and economic disparity. For this reason, he indirectly advises young writers to not only write for themselves (i.e., out of a need for expression), but also to contribute positive change to society.
http://orwell.ru/library/essays/wiw/english/e_wiw

https://www.brainpickings.org/2012/06/25/george-orwell-why-i-write/