It obviously dependents on priors, and figuring out realistic ones is kind of the point. We haven't observed other life in the universe, so any result of adding

It obviously dependents on priors, and figuring out realistic ones is kind of the point. We haven't observed other life in the universe, so any result of adding up all those chances necessarily has to be low. The question is what makes it so low. And most importantly: Is it a check we humans already cleared or something still coming? That should be a huge warning to us.