What were the disadvantages of trade routes between East and West, which were used by merchants before the Great

What were the disadvantages of trade routes between East and West, which were used by merchants before the Great Geographical Discoveries? What served as a prerequisite for the active development of banking in Antwerp in the 16th century.

The disadvantages of trade routes were that they took a very long time. In addition, great dangers awaited the merchants on the way. Moreover, it should be remembered that trade with the eastern countries was also hampered by the fact that at that time there was a great confrontation between the West and the East because of the Crusades. Thus, the only safe route was sea trade. But then European traders did not know the sea route to India. We can say that the geographical discoveries were the result of a great need for the development of world trade.