Hydroponics have been shown to be a successful technique for growing of plants. Yet most of the crops are still grown on land. Why?

Hydroponics or Soil less culture of a plant is the technique in which the plants are grown in mineral nutrient solution instead of soil.Many plants are grown using this technique like tomato,lettuce,cucumber etc. but this type of culture requires regular addition of mineral and change of water which is quite a hectic schedule.Most of the crops are still grown on land because the soil does not need regular addition of mineral and change of water it is already present.Hence, it is a convenient method.