My problem with the argument of "chance", ignoring that we are drawing such probabilities from limited information & assumptions that life forms must have the same environment as earthlings...
Is that while it's true that the odds of a particular individual existing are low, the odds of any individual existing are high. In order for any human to exist, they must be an incredibly lucky sperm dispatched at the perfect time for fertilization. Just based on those metrics alone, all humans are very lucky to exist at all. However, given that most humans do reproduce, the odds of any human existing are quite high. More specifically, being unlikely to exist doesn't necessarily mean existence is unlikely.