Consciousness is functional, it is a “tool.” It is not some sort of learning machine detached from survival and biology.
Consciousness is identification — identification of what is in its environment for the sake of the survival of an organism in a species-appropriate way. It is an aspect of the organism, not something separate. It identifies what is in the world, what is good for the organism, and what is bad. Evaluation (conceptual only for humans; pre-conceptual for other animals as well as the human) is wrapped up in consciousness, as is movement and control/regulation.
It identifies what is in its environment locally, in part (individual things) and in whole (that “all at once” aspect of perception, e.g., the surrounding background to any act of looking at something) — though, in virtue of concepts, humans can reason beyond that.
Plato was wrong, Darwin was right.
(The nervous system more broadly also keeps the organism functioning, and keeps all “parts”of the organism working together, and connects internal to external, all within certain limits (temperature, pressure, electromagnetic radiation, energy, materials, etc.).)