The stars all have a purpose that benefits us, even though we may never see their true form or essence. They assist us with their light, even though that light—in of itself—is old, weary, and meaningless. While their precise nature is irrelevant, their impact is phenomenal.
That is how I see humanity. While we may not interact with the vast majority of humans on our planet, they were all placed there for our benefit. And while people enter and exist our lives almost without notice, like the stars in the night sky, I believe they were all put here for a reason.