Can't really answer why any of us were born, but one thing is certain.
You have this life, and you'll only get one. Once you're gone, eons will pass and you will never be able to do anything again. You'll never have another experience again; you'll never breathe again, you'll never feel again, you'll never think again. And sadly, that's how it is for all of us and no one can avoid it.
The only thing that you (or any of us) can do right now is live the life that you were given.
So I guess it's time for a short story. Several years ago, I thought of committing suicide. I was wondering the same thing you were wondering and nothing was coming up. I thought that the world would be a better place without me, so as my duty to improve it for others, I should have just killed myself. Fortunately, I was in public while everything was floating around in my head, and I didn't want anyone to know that I was going to kill myself, so I couldn't do anything then. I cooled down later and decided that I'd try and mix things up since I was going to die soon anyway. I started talking to people and trying to make them feel better, even if it meant making myself feel worse. Honestly, every time I made someone happier, it felt good. I said "screw it" to the whole suicide thing and thought that even if this life was just to make others happy and didn't help me at all in the long run, then I should still live it because I won't get another chance. That was my revelation. Today, I'm so incredibly happy that I didn't go through with any of the suicidal thoughts I had. Since then, some things have changed. I've met some new people, sparked some new friendships, and met someone so amazing that I can't explain it in words.
And that's it. I hope some part of this has had an impact on you.