What are you talking about? You're only here because someone "sacrificed their life" (how misanthropic, now I kind of hope you never do have kids if that's how you view them) to raise you. We're all only here now because people have been having kids for thousands of years, it's our most core, basic survival instinct and the one and only objectively "necessary" thing that exists in this world (unless you believe in complete human extinction).