"The sunset is infinitely beautiful and buried by the coming night" expresses the poet's love for nature and his pursuit and yearning for beautiful things. Although the sunset is beautiful, it is a pity that it is dusk and cannot stay long. The meaning of this poem is the poet's enthusiasm for life, persistence in the world and persistence in ideals. What the poet wants to express is an optimistic and positive attitude, not a negative attitude, so it is not sadness.
"to see the sun, for all his glory, buried by the coming night" means that I was depressed in the evening and drove to the ancient suburbs. The scenery in the setting sun is infinitely beautiful, but it is near dusk.