Why is it said that the content of poetry written in prose subverts the traditional concept of poetry?

Different language use, different expression methods, etc.

The use of language is different: traditional poetry usually pursues the rhythm, rhythm and beauty of language, while new poetry pays more attention to the freedom, nature and simplicity of language.

The language of new poetry is closer to life and daily language. This way of using language makes poetry easier to understand and accept, and at the same time breaks the limitations and constraints of traditional poetry language.

Different expression methods: Traditional poetry usually uses relatively fixed expression methods and techniques, such as symbolism, metaphor, antithesis, etc., while the expression methods of new poetry are more flexible and diverse, and can include narrative, description, discussion and other methods.

This way of expression makes the new poetry more expressive and infectious, and can better express the author's inner world and emotional experience.