Why do frontier poems in prosperous Tang Dynasty represent poems in prosperous Tang Dynasty?

Poetry in the prosperous Tang Dynasty represents the highest achievement of Tang poetry. Although it is only forty or fifty years, it is a golden age in the history of poetry development. Poetry in the prosperous Tang Dynasty is divided into two schools: pastoral poetry and frontier poetry. Landscape pastoral poetry is represented by Wang Wei and Meng Haoran, frontier poetry is represented by Gao Shi and Cen Can, and other important poets of frontier poetry school are Wang Changling, William Wang and Wang Zhihuan. Frontier Poetry School refers to the poems describing the frontier wars, frontier life, frontier scenery and frontier folk customs of frontier soldiers. The society in the Tang Dynasty was open, and most of the literati were uninhibited. Most literati, such as Li Bai, Du Fu and Li He, also have the idea of joining the army to serve the country, so they occupy a major position and are the representatives of poetry in the prosperous Tang Dynasty. After all, pastoral poetry is the thought of a few poets and cannot be a representative.