Why is Kafka called "the father of western modernist literature"

Influenced by Nietzsche and Bergson's philosophy, Kafka has always been a bystander of political events. Therefore, most of his works express isolated and desperate individuals surrounded by hostile social environment with grotesque and absurd images and symbolic intuition. His writing is clear and imaginative, and he often uses fables. The moral behind it is that people are different and there is no (or never) conclusion, which makes all kinds of writing schools in the twentieth century recognize him as a pioneer. His writing style is expressionism, and he is one of the most successful expressionist writers. The main period of his life and creation was around the First World War, when economic depression, social corruption and people's poverty made Kafka live in pain and loneliness all his life. Therefore, strangeness, loneliness and fear of society have become the eternal themes of his creation.