What was the major function of ancient mecca and why did it flourish?

Even before Prophet Muhammad was born, and the Islam was founded, Mecca was one of the most important and sacred cities in the Arabian peninsula because people pilgrimaged to the Kaaba (the most important mosque, built by Abraham and Ishmael) and visited the collection of stone idols located around the Kaaba that represented the different deities of their religion (before Islam was installed, Arab people were not monotheist). Mecca flourished because it was a religious center and due to its connection to South Arabia, East Africa and South Asia and to the large number of visitors it received, it became a trade route.