Why is Du Fu called a poet and saint? Why are Du Fu's poems called epics?

Du Fu was a great realistic poet in Tang Dynasty in China. He lived in the historical period from prosperity to decline in the Tang Dynasty. He loves life, people and the great rivers and mountains of the motherland. He hated evil, criticized and exposed the corruption of the imperial court and the dark phenomenon in social life. He sympathized with the people and even fantasized that he was willing to make self-sacrifice to save their suffering. Therefore, his poetry creation always runs through the main line of worrying about the country and the people, with the most ordinary people as the protagonist, which shows Du Fu's greatness. His poems are rich in social content, strong times color and distinct political inclination, which truly and profoundly reflect the political current affairs and broad social life picture of a historical era before and after the An Shi Rebellion, and reveal social turmoil, political darkness and people's sufferings. He is known as "the history of poetry". He is good at using many systems of classical poetry and creatively developing them. He was the pioneer of the new Yuefu poetry style, and his Yuefu poems contributed to the new Yuefu movement in the middle Tang Dynasty. Du Fu was concerned about the country and people all his life, with noble personality and exquisite poetic skills, and was honored as a "poet saint" by later generations. Du Fu left more than 1400 poems to later generations, covering every corner of social life in the Tang Dynasty, especially his works before and after the Anshi Rebellion, such as Three Officials Farewell and Three Farewells, Two Roads for the Road, Military Vehicle Shop, Northern Expedition, and From Beijing to Fengxian, reciting 500 words, which linked personal feelings with major historical events. The word "poetic history" was used for the first time in Bai Meng's Poems of Talented Talents in the Tang Dynasty to summarize the ideological and content characteristics of Du Fu's poems, but it mainly focused on "detailed notes". Song people expounded the concept of "poetic history" from different angles. They often ignore the artistic features of poetry, but they all notice that Du Fu's poems are related to major historical events. Du Fu provided us with a true picture of the history of the Tang Dynasty with his broad ideological content and historical recording techniques different from those of historical books. He used his unique brushwork and his unique breadth and depth to supplement the shortcomings of history. As Hao Jing, a scholar in the Ming Dynasty, said, "The past was called the history of poetry, so that it was not necessarily so soft for Banma to remember."