re: A unique object
Even the Rare Earthers like Ward and Brownlee contend that many worlds probably contain at least simple life forms, that's how pervasive the materials and formation scenarios for life are in the Universe.
In this case, it only takes a few to survive to develop more advanced beings who may one day explore and colonize their galaxies. We are certainly aimed in that direction.
Jut like with creatures who lay thousands of eggs or release millions of seeds, most will not survive, but it only takes those few who do to carry on the species. And that has been going on successfully for millions of years on Earth.