Why were the straits between the aegean and the black seas so important to the byzantines?

Allowed them to control movement from Mediterranean and Black Sea --> control trade routes leading to Asia & Europe. Those straights controlled most of the trading between the middle east and Europe. A ship is a lot more efficient than trudging though a desert right? So Byzantine could control trading and commerce and they will became the trading capitol of the world.

The fact that farmers were paid for destroying crops.