Consciousness is the Supreme Mystery. Without Consciousness nothing would or could exist. You might think that is not true, as there is always someone else that is conscious. But what if no other being was conscious? Not animals, plants, minerals - no consciousness anywhere. How could anything exist if there is no conscious being to be aware of it’s presence? This is not as simple as wondering if a tree falling in the forest makes a sound if no one is there to hear it crash to the ground. That depends on your definition of what a sound is. So the question of consciousness depends on your definition of existence. What is reality?
In fact, it does not matter what your defintion of reality is. Reality is what it is regardless of your definition. Your understanding of existence will depend on how aligned your definition is with the actual truth of what reality is.