Au Contraire,

I don't think we have any evidence that either life, or the more narrow subset of sentient life is in any way rare.

In my considered opinion, what is rare is technological, egotistical, energy-inefficient civilisations.

In order to be detectable by SETI, the civilisation needs to be wasting huge amounts of energy transmitting in arbitrary directions. As we've seen with the evolution of technology, wasted energy is something to be avoided. Accidental transmissions have a limited time and distance window of detectability. Deliberate transmissions require assumptions about the nature of the civilisation which go beyond mere sentience.

My own research into the nature of planets suggests that the vast bulk of life will be found on waterworlds, which are unsuitable for the development of electricity, smelting, telescopes, rocketry...

This doesn't mean that there is not intelligent life there. Imagine something close to the world of Disney's "little mermaid". Coral cities under the sea grown to order by organisms serving the city dwellers, who work flint, use kelp for spear shafts and clothing, use fish bones and teeth for tools and jewelery and have rich complex social lives and communicate by sound and vibration over long distances through ocean waveguides.

In short, most of the potential life in the universe is stuck on the wrong sorts of world to even think about communicating with us.

I believe that the failure of SETI tells us that Earth is an unusual example of life in an unusual place which has forced us into a non-standard evolution path.

Not Unique - just rare enough that the next one in time and space is too far away to casually communicate.

And we can further conclude that either interstellar travel is very unlikely, or we are amongst the first civilisations in our corner of the galaxy to begin to think about the idea.

That's my analysis of Germi's apparent paradox - which is actually a data point as important for the idea of SETI as Olber's paradox* was for the nature and origin of the Universe.

(For those unfamiliar with the subject, Olber's paradox is that if the universe were infinite in time and space - or even simply very large in both, then the night sky would be as bright as the disk of the Sun and the Universe would die in a radiative heat bath.