There were three major reasons why it faded.
The first was the final fall of Constantinople in 1453, ending the last remnant of the original Roman Empire. This made trade with Europe harder.
The second was the development, initially by the Portuguese but followed by others, of direct sea routes to India, and then China, which bypassed the much more expensive land routes.
The third was the opening up of the Americas as potential sources of commodities.
The result was a long-term economic and military decline of areas like the Middle East. The extent of which was not realized by the West until Napoleon conquered Egypt.