The chance of us being the only living organisms in the universe is extremely small and that the necessary ingredients for life as we know it are extremely common all over the universe. We are not likely alone in the universe if you look at how common the ingredients of life are.
Hydrogen, oxygen, nitrogen, carbon is the foundation of organic chemistry, carbon-based life. These ingedients are everywhere we look in the univers. Whatever happened on Earth, it is not likely to be rare or unique.
We will not find advanced super aliens with spaceships flying around but rather microorganisms. The universe has been around 14 billion years – plenty of time to evolve all kind of creatures out there, particularly microorganisms.
We have no reason to not think of microorganisms as aliens. They do not need to have built a spaceship, theya are just alien life on another planet.