What are the reasons for the decline of poetry after the Song Dynasty?

After the Song Dynasty, poetry showed a declining trend. The main problem is the lack of innovative consciousness. No matter in content, subject matter, artistic style or genre form, we have not been able to get rid of the stereotype of our predecessors. Many writers simply aim at ancient customs, and even the unconventional spirit of the Song people has been lost. However, the number of works of these generations is still quite amazing. There are more than 4,000 poets recorded in Chronicle of Ming Poetry alone, almost twice as many as the whole Tang poetry, so excellent writers' works are still emerging. The Jin dynasty was short-lived, with frequent wars, underdeveloped culture and low achievements in poetry. It's just that Yuan Haowen at the end of the term still has some good works that can reflect the times, and the style is rather tragic.