Why did trade along the Indian Ocean contribute to the growth of states?

A large variety of substance were transported within an easy route

Explanation:

The Indian Ocean trade routes connected Southeast Asia, India, Arabia, and East Africa, beginning at least as early as the third century BCE. ... Domestication of the camel helped bring coastal trade goods such as silk, porcelain, spices, slaves, incense, and ivory to inland empires, as well.

The dhow trade was particularly important in the western Indian Ocean, where those vessels could take advantage of the monsoon winds; a great variety of products were transported between ports on the coast of East Africa and ports on the Arabian Peninsula and on the west coast of India (notably Mumbai, Mangaluru ( ...

supplies had to travel a long distance across water on ships that were often attacked, so they did not reach europe

uncle sam would be tossing and turning in his grave : *)