You have flipped and distorted the theory, now saying that life is essential to the presence of water.
Liberté. Égalité. Fraternité.
With the evidence we now have, the probability is that life here is unique .
If I find a grain of gold on a huge beach of billions of grains of sand I can not assert any probability that I will find another ... no matter how numerous the possibilities are. If I find another gold grain within say a nine square meter section I can assign a probability of finding a third on that beach. But with evidence of only one I can not, no matter how big the beach is.
Many possibilities does not indicate any change in probabilities.
You claimed "a profound lack of any kind of evidence that supports that notion." That's a false statement, as it ignores indirect evidence pointing toward a near certainty of alien life of some kind.