If we're hallucinating our reality what's the point of the hallucination?

Today I don't feel like it's that extreme of a take to say that consciousness is a "hallucination" or simulation that our brain is creating of the outside world. What I want to know is why the brain does this. We know the brain is capable of performing complex actions without being conscious. So is the hallucination an accidental byproduct, or is the brain actually referring back to it?