EUR 4.-What is the benefit of consciousness if consciousness does not seem necessary for surviving in the real world?

Today at the AI Lab an interesting discussion took place I attended in the background:

One researcher was arguing, that being conscious was actually not a necessary condition to intelligently act and behave in the real world. One could build an artficial human perfectly capable of all the he features and facets a normal human is cabable of, however, a program would control the human deciding in each situation what to do. A smart learning algorithm would learn and decide, the only difference would be, that this hypothetical human would not be conscious. A question then arouse:

Question: What is the benefit of consciousness at all, if consciousness could be avoided and does not seem necessary for behaving in the world? Think of single cell organisms or animals without consciousness.

Thanks for short solutions and interesting thoughts on the problem. I am very curious to learn your opinion.