Why has HYDROPONICS not succeeded in eliminating FOOD SCARCITY in the World??

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It has the capability to be deployed in the seas and other wayer bodies which constitute about 2/3 of the Earth's Surface !

Its practice eliminates WATER SUPPLY which is CRITICAL in delivering agricultural , productivity , especially in the ARID regions of the World!

This is "HYDROPONICS" a , tech initiative which grows crops/ plants directly on the WATER without recourse to the SOIL for anchorage .

Why has it not been able to address the food challenges of the world???