If we live in a mathematically ordered universe where similar self-forming and organizing patterns are common, why should the earth be exceptional?
All elements exhibit the same relational properties throughout the universe. It is impossible that bio-chemistry follows different interactive mechanics in similar environments.
Just look at all the different environments have come and gone on earth and the variety of differently capable living organisms it has spawned.
The earth has formed organisms that are almost indestructible, albeit very simple.
As I said, intelligent life may be very rare, but I am willing to bet that life itself is common throughout the universe.
And once life starts and must compete for resources, evolution via natural selection follows the same universal probabilistic processes.
The universe is more the same than it is different!
In what way could the earth be different from any of the other 700 quintillion planets, each capable of performing say 2 trillion, quadrillion, quadrillion, quadrillion chemical experiments over their lifetimes, with many planets being older than earth and having had more time for Peabody chemistry at planetary scales.
Note that bio-molecules are already being formed in interstellar clouds. Planets are not even necessary for biochemistry to occur.
The point is that the Table of elements from which all physics originate is the same throughout the universe.
We are dealing with probabilities spread out over an astronomical range of environments. The earth is not exceptionally different from other planets and from examples on earth alone, there is no indication that only a very specific and narrow ecology is required for life to originate.
How many biochemical proto-life forms have originated on earth? No one knows. They have faded into the mist of time without leaving a trace.
Anybody that claims the earth is unique does not understand the concept of a dynamic universe and is still stuck on the concept of earth as the center of EVERYTHING, including life. i.e. a religious interpretation.