We might ask "what else do we expect it to do?" A second person perspective makes even less sense. And since the brain's activity entails first-person-perspective-like processing, the next most obvious answer, no perspective at all, isn't plausible either. It's reasonable that the brain would produce a first person perspective as it thinks about its situation. (And you don't have extend this to objects that don't think, by the way, if you were thinking of doing that.)

But I'm still left with the impression that there's an unanswered question which this one was only standing in for. The question is probably "what is thinking, anyway?".

Or, something quite different: "Why don't I have the outside observer point of view?". It's somehow difficult to accept that when there are many points of view scattered across space (and time), you have a specific one, and don't have all of them: "why am I not omniscient?". It's egotistical to expect not to have a specific viewpoint, and yet it seems arbitrary (and thus inexplicable) that you do have one. But again, the real question is not "why is this so?" but "why does this seem like a problem?".

If you define consciousness as the stream of perceived experiences coming from the physical body (sights, sounds, touch, and even thoughts, including even the thought that you're in control), it's expected each body would have its own consciousness? The OP article about split-brain experiments also (very counterintuitively) indicates that at least some thoughts are perceived rather than something you're actively doing?

I agree that this question is mysterious and fascinating, I just don't think the question of forking your consciousness bears on it at all.

The fact that first-person perspective exists is probably the fact that I am most grateful for out of all the facts that have ever been facts.

But I don't have any difficulty imagining forking myself into 2 copies that have a shared past and different futures.