There is way more life in the universe than most people think. Probably bugsize creatures on other planets in our solar system, entirely different bases for evolution (no dna) some other place far away. It’s not really a matter of believing anymore since evolution is more a compound law of nature than it is an historical fact. Time causes systems to evolve and the universe is filled with energy. There are suns that are a million times bigger than our sun with probably a million planets orbiting them. We haven’t even found the edge of the universe yet.
Intelligence, though probably also inevitable, is far more rare. This is because it requires a mild yet unforgiving environment to teach the lifeform every trick in the book. I used to wonder why dinosaurs hadn’t developed a higher intelligence when they were so much bigger but they were probably evolving their brains right alongside our ratlike ancestors. This probably means that intelligent life requires approximately 4 billion years of evolution. THAT is a long time, even for planets.
If we are going to find intelligent life we are going to find it in the ether, not on a planet.