Why didn’t punctuation marks be invented in ancient China?

There were punctuation marks in ancient China, but the punctuation forms were not uniform.

In the "Hou Ma Meng Shu" of the Spring and Autumn Period, one or two short lines are used to indicate heavy text, which is a type of punctuation.

The Han Dynasty invented the "sentence reading" symbol. A short paragraph with complete meaning is called "sentence"; a paragraph with unfinished meaning in the sentence and the tone can be paused is called "reading" (pronounced, equivalent to today's comma). The Song Dynasty used ".", "," to express sentence reading. It was not until the Ming Dynasty that names of people and places appeared. These are the earliest punctuation marks in our country.

In the "Yongle Dadian" of the Ming Dynasty, the small red circle in the picture is a kind of punctuation.

The 1919 Preparatory Conference for the Unification of the Mandarin Language specified 12 types of symbols based on my country’s original punctuation marks and with reference to the punctuation marks commonly used in various countries, and was promulgated nationwide by the Ministry of Education at that time. After the founding of the People's Republic of China, the General Administration of Press further summarized the usage rules of punctuation marks and published "The Usage of Punctuation Marks" in 1951. In October of the same year, the Government Affairs Council issued the "Instructions on Learning the Usage of Punctuation Marks." Since then, punctuation marks have become more perfect and have a unified usage. In April 1990, the National Language Working Committee and the Press and Publication Administration revised and promulgated the "Usage of Punctuation Marks", which made new regulations and explanations on punctuation marks and their usage.