Answer:
Umm prolly coz people needed to move to different places and build homes, for example, in the Vedic period, the Indo Aryans originally were in central Asia and the people kept speaking Indo European languages they were kicked out and went to the south side of Asia for a home and a place to live in. This is prolly why civilizations developed, so that people could create their traditions and they could have a leader and that they could live life desired by them.
Explanation:
