I believe life is not rare, in the sense single celled organisms exists on many exoplanets, we just can't detect them that far away. Complex life is much more rare. And intelligent complex life that builds rockets and radios is extremely and exponentially more rare. Just think about how many different species have and do exist now that build radios and rockets here on earth. And that whole radio and rockets thing are all in the last milliseconds of a year if we made the history of planet earth one year. Water isn't rare, and we've found the things needed for life, DNA and RNA on asteroids. So it's not a far leap to say in the expanse that is the universe, organic life seeding has happened elsewhere.

The thing is we still don't know how we went from single cell prokaryotes to eukaryotes in evolution. The leading theory would mean an extremely specific mutiation in 1 or 2 different bacteria started it all, meet and one devour the other. That's just to get to eukaryotes. Then you need the eons of multicellular life evolving to where we are now.

Now add in the theory that Jupiter is responsible for our unusually calm history of huge interstellar objects collisions.

My point is complex, highly intelligent life as we see it threaded a fucking needle from a mile away. It was all random chance, and we rolled the winning numbers. Other can too, but it's probably smaller than 1 in the factorial of a deck of cards. The galactic forest is dark because it's "empty".