For simple, monotonous tasks, robots are indeed far superior to humans.
For more complex tasks that involve flexibility and high level pattern recognition, humans as so far above robots on a work/watt basis it is silly. We have been developed by millions of years of evolution as efficient foragers.
Of course, if you take the complexity and pattern recognition out of farming you make it amenable to machines. An unfortunate side effect of this is that the farming practice becomes unsustainable.
For more complex tasks that involve flexibility and high level pattern recognition, humans as so far above robots on a work/watt basis it is silly. We have been developed by millions of years of evolution as efficient foragers.
Of course, if you take the complexity and pattern recognition out of farming you make it amenable to machines. An unfortunate side effect of this is that the farming practice becomes unsustainable.