What is the reason why there is no detailed leather technology in ancient literature?

There is no detailed record of leather technology in ancient literature, which may be as follows: First, this technology is too old and neglected. Secondly, in feudal society, there was a long-standing concept of belittling manual labor and skills, and tanning technology was the dirtiest and most tiring of traditional technologies. Third, more importantly, when linen, silk and cotton textiles came out, leather products with limited raw materials, complex manufacturing technology, great difficulty and low output could only occupy a very secondary position in the clothing industry.