Among many flaws in the logic, the biggest is that you're assuming all aliens would be civilized humanoid type beings.

A superior race would exist theoretically given it had enough time to evolve, but another requirement would be the environment and a necessity to become humanoid.

Consider how long the dinosaurs ruled this planet. A similar species would lack the biological qualities (opposable thumbs, large frontal lobe of the brain etc) to create\fly a UFO. It's not to say there couldn't be some form of sophisticated life on another planet though that has had the right conditions to be human-like (in regards to the aforementioned traits), just that they might not give a shit about life on our planet. If we're 1% different from apes that evolved from a mutual ancestor, another 1% difference favorable to a higher species would mean we're just idiots and not worth the time\effort to investigate at this point in our development.

Most likely, we've only been civilized for 200000 years at the most. That's a drop in the ocean compared to how long other planets could have been developing life.