For four billion years, life on Earth was microscopic blobs of goo.
Then 600 million years ago - BAM - complex life emerged pretty much in the blink of an eye.
We have no idea how likely that transition to complex life 600 million years ago was - we have a sample size of ONE.
Now go back an read my first sentence: For four billion years, life on Earth was microscopic blobs of goo.
That four billion years was about half the expected lifetime of the Earth. The probability that complex life evolves may very well be infinitesimally small. WE DON'T KNOW.
Believing the universe must be teeming with intelligence is based on nothing more than faith.
Actually, the odds are worse than that. Mass extinctions have happened with monotonous regularity in the history of the world, and only comparatively recently have life forms evolved with internal skeletons that enabled them to get to be quite big. Insects and arthropods probably don't get big enough to carry large enough brains to become intelligent, but arthropods seem to evolve a lot more easily than do vertebrates.
Even when you look at vertebrates, a tendency to evolve big brains seems to be exclusively a mammal thing. Dinosaurs seem to have been ancestrally warm-blooded, ditto crocodilians and so on, but dinosaurs plot right on the expected brain to body size ratio that reptiles have. Throughout the entire age of dinosaurs there never seems to have been any sort of intelligence arms-race developed. Early in the post-dinosaur age, just such an arms race developed with mammals, forcing quite a lot to become smarter over quite a short period of time.
There's two reasons to doubt the inevitability of intelligence developing on alien worlds. There may well be plenty of life, but life more advanced than bacteria will be rare, and intelligent life vanishingly so.