It's easy to throw up our hands and say, "sure, why not," as if there must certainly be other inhabitants out there, and that it would be unreasonable to think this planet alone may be the apple of God's eye and the focus of the entire universe, but I don't think astronomers concur.
There are hundreds of necessary parameters for planets to host physical life, yet for the trillions of stars we observe, there are few detectable planets orbiting them, and none qualify. No, Earth is unique in its proximity to the sun, composition, environmental cycles and even its orbit and tilt. As astronomer Dr. Hugh Ross put it, the likelihood of another habitable planet is one in 10,282. Lemme say that this is about nil.
I was in Santa Barbara once, and a group of us witnessed a UFO that defied physics with a 90° sudden change in direction. While unconvinced that what we saw was extraterrestrial, I don't doubt that nonphysical malevolent entities exist who would deceive people with the pretense of space travel.