I think any and all assumptions about “no proof” of extraterrestrial life are overtly trite.
Look at all of the biodiversity on just this planet. further, look how interconnected and dependent the entire bio system is. now why would humans, even begin to think that outside of ocular perception (including very juvenile instruments) and planet earth, the interconnectedness of biodiversity is disrupted by what humans call “light years”?
Think about this: an ant will NEVER know the world, life or existence of a whale but yet they occupy and dwell in the same plane of existence. to either the ant or whale, each is outside of any knowledge base, and/or sensory perception to acknowledge the others presence but yet they both live just within a 24,000 mile globe.
Humans and extraterrestrials could express the same parallels of being — duh.
Another thought: we live 3rd planet from the sun, and happen to also have a vibratory existence in the 3rd dimension. What if my dear watson, each planet represented a different dimension. Meaning that mars, the 4th planet, is actually TEAMING with life, but life that has a vibratory resonance in the 4th dimension that of which we cannot “see” in this dimension?
Humans are stupid and I desperately need to find the keys to my space ship!
*** drops the mic and walks away ***