This is a great question and whenever I ponder it I think about several facts.
1 - The universe is vast but science proves that it is finite is expanding and will eventually contract at some point.
2 - The possibility of life elsewhere in the cosmos is a mathematical certainty. The "Drake Equation"
3 - There is no concrete irrefutable proof that there is "intelligent" life anywhere other than on Earth. The "Fermi Paradox".
4 - If such life existed and it arrived on Earth without sufficient preparation, it would be a disaster for humanity. Just look at our own the history of contact.
5 - Time is vast so it is possible that another intelligent civilization flourished and then succumbed.
6 - The best we can hope for is to either be the most recent intelligence to arise or to be the first intelligence civilization in existence.