Why did the changes in calligraphy in the late Western Zhou Dynasty not only exist in style, but also in system?

The change of calligraphy in the late Western Zhou Dynasty lies not only in style, but also in system. Most of the artifacts in the Western Zhou Dynasty are related to Wang's tribute. However, in the late Western Zhou Dynasty, vassal artifacts began to appear. On the contrary, the bronzes related to Zhou Wang declined sharply in the Wang You era. Warlords did not follow the typical styles, such as Chu Da Lin Zhong, reverse casting, Lu Boda, Ding, Suprenza and so on. And then they are embedded in it, and so is their decline.