Pythonic,
Actually your assumption is just parroting a bunch of cynics, technocrats and scientific skeptics, but in reality it is not always true. For example the video evidence out there is obviously filled with hoaxes, but you would still consider a You Tube video better than a report from an Air Force pilot?
Or let's take the UFO out of equation altogether. Stand outside looking up a the dark sky some night. With good eyes you can observe satellites passing over. When you see one try to take a picture of it with your cell phone. Then ask yourself if you believe your cell phone picture or your own eyes.
Human perception is much better than the cynics and skeptics give it credit for. It is based on well known scientific principles with known tolerances. That is why optometrists can measure eyesight and if necessary create perfect lenses for glasses. There are many instances when eyewitness tesimony may be better than material evidence.
Not only that, material evidence can also lead to false conclusions. A strand of hair at a crime scene doesn't prove the person it came from committted the crime. If that person was on the other side of the planet and seen by numerous independent witnesses, that person will not be convicted on mere trace evidence ... physical or not.
Be careful about using absolutes like "worst" or "always" when you are making statements, otherwise you'll run into trouble. Think for yourself.