What was the trade situation between East and West before the opening of the new air route?

Before the new air route was opened, East-West trade was very frequent. Raw silk and porcelain from China are very popular in western markets, and the prices of cinnamon and spices are also high. At that time, East-West trade was conducted by two land routes and one waterway, which could be carried out along the westward route of the Silk Road and Xuanzang, or along the westward route of Zheng Along and Hefei. However, after the rise of Byzantine Empire and Turkish Empire, the trade between East and West was monopolized, so the original trade routes between East and West were blocked, resulting in

As early as15th century ago, Europe and Asia had trade contacts, and there were three main trade routes: one was a complete land route from Central Asia along the Caspian Sea and the Black Sea coast to Asia; The other two are amphibious. One first goes to the Persian Gulf by sea, and then to Syria on the east coast of the Mediterranean through the two river basins. The other enters the Red Sea from the sea, and then passes through the Isthmus of Suez to Alexandria, Egypt. These three trade routes finally converge in the eastern coastal areas of the Mediterranean, where oriental goods generally arrive first and then transfer to Europe. At that time, oriental commodities, such as spices, camphor, sandalwood, silk, precious stones, cloth and so on. It is very popular in the European market and a necessity for the upper class. However, after repeated handshakes by Persians, Arabs, Eastern Romans and Italians, the price rose again and again and became an extremely expensive luxury. At that time, East-West trade was basically monopolized by Italians and Arab businessmen. If European businessmen want to directly manage oriental goods and monopolize huge profits, they can only bypass Arab and Italian businessmen and find another way. What's more, after the middle of15th century, the Ottoman Empire was powerful and controlled the hub of the Asian-European trade route. Although the traditional East-West trade was not completely interrupted, the normal business order was destroyed by the extortion and long-term war of the Turks, and business travel stopped. Since then, the quantity of goods shipped from the east to Europe has decreased sharply, but the price has risen rapidly. The upper class in Europe has always regarded oriental luxury goods as necessities of life and bought them in large quantities at high prices, resulting in a serious trade surplus, a large outflow of precious metals and unbearable financial burden. In addition, western European businessmen and consumers have long complained about the Italian and Arab businessmen who exploited them, so countries have taken actions in succession, hoping to find another way and open up a new air route that can bypass the Mediterranean and reach the East.