The Drake Equation of some years ago was an attempt to calculate the number of advanced civilizations in our galaxy that might be able to communicate at radio frequencies. No one knew those variables either, so he just plugged-in what he thought were very conservative values. My own feeling is that he overestimated them, but clearly, he - and I - thought it was plausible to do this.
It’s not necessary to assign a specific value to ascertain a “feeling” for the sense of probabilities overall, in the sense that we would use the word “probably” to assign a wide range of possibilities to as wide a range of considerations in general without having any definite idea of the actual odds determining their outcomes.
With this in mind just consider our place in the universe. We’re just out from the middle of a spiral galaxy where in it’s outer reaches metals would be very poor given the paucity of middle generation stars. Wherein too were we closer in toward the galactic center we wouldn’t be able to see outside it and the danger of cosmic collisions would be higher given the greater density.
We’re in a solar system with a large outer planet like Jupiter that sweeps up a lot of debris that we otherwise might have to be faced with.
We’re on a planet with plate tectonics which recycles and conversely reproduces oceanic crust without which chemical processes we likely wouldn’t be around to discuss them to begin with.
We have a Moon much larger than average size for our planet which stabilizes our precession yielding us seasons, allows us test relativity during solar eclipses….
There are myriad features all about us from the sub-microscopic to the universe at large that can be viewed in terms of probabilities, many of them fantastic.
And I’ll bet that God is behind them all.
Thoughtful, but you completely missed the point. And intentionally, at that.