It keeps us from paranoid panic every time there is a solar or lunar eclipse or a lightning strike. It keeps us from running around casting spells on each other or burning people at the stake or throwing people into ponds to see if they float. No myths, legends, fantasies, superstitions, fairy tales, just the facts. Science is a method of discovering the truth, religions claim to already have the truth. Atheism is fact like evolution is fact.
Evolution is fact like a round earth is fact.
If extraterrestrial intelligence exists, the likelihood that they would follow one of the religions here on earth is about as likely as them wearing tartan kilts and playing bag pipes, yet it is perfectly feasible that they could be atheists. The concept of catholic or shite or Jehovahs' witness aliens is absurd. There is no way aliens would follow any of the religions here on earth, if they have religions they will obviously be different religions to any here on earth, yet they could easily be atheists. Atheism is atheism throughout the universe. Only atheism can be cosmic.