How has deciphering thee discovery and deciphering of ancient writing to form our understanding of urban life in ancient china and mesoamerica?

Without the ability to read ancient Chinese and Maya text, we would be limited to archeological findings and guesses made based on them. The fact, that we can read ancient texts, let us know for example:

the names and times of rule of many rulers,
the religious practices
some events from the past
some cultural and technological inventions such as their knowledge of astronomy
the social composition of the society

Our knowledge of urban live comes from the description of customs and occational information about who lived where and how much was paid for what services