Of course, you can think of consciousness as analogous to excitation of a field, and, like the electromagnetic field or gravitational field, there is no center, and everything is interconnected. And yet, like every particle is ultimately a wave in disguise, we can still meaningfully talk about individual particles, because some waves do behave that way sometimes.
An individual consciousness is particle-like. As a shorthand for “this relatively independent packet of consciousness which has measurable distinctiveness from other packets and does not freely share perceptions or memories with them,” it’s often more practical just to say “I” instead.
It’s a reference.