Why does Qin language play an important role in the history of Chinese character development?

Shi Guwen and other Qin stone carvings and Qin cemetery stone carvings are huge, ranking first in stone carving calligraphy. From the wooden slips in Qingchuan to the Qin slips in Yunmeng Crouching Tiger Land, to the Qin slips in Liye, and then to Han Li, the evolution of official script runs through. Qin characters play an important role in the development history of Chinese characters.