Because in the Ancient East, scientific knowledge was used to solve practical problems: the construction of pyramids and magnificent temples, the design of an irrigation system. Also, thanks to science, medicine developed, and ancient Egyptian astronomers learned how to accurately calculate the beginning of the flood season of the Nile, which is very important for the agriculture of Egypt. Astronomers of Mesopotamia laid the foundations for the calendar. A seismograph and a compass were invented, which made it possible to navigate the terrain. And much more.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.