The Fermi paradox (or Fermi's paradox) is the apparent contradiction between high estimates of the probability of the existence of extraterrestrial civilization and humanity's lack of contact with, or evidence for, such civilizations.[1] The basic points of the argument, made by physicists Enrico Fermi and Michael H. Hart, are:
The Sun is a young star. There are billions of stars in the galaxy that are billions of years older;
Some of these stars likely have Earth-like planets[2] which, if the Earth is typical, may develop intelligent life;
Presumably some of these civilizations will develop interstellar travel, a technology Earth is investigating even now;
At any practical pace of interstellar travel, the galaxy can be completely colonized in a few tens of millions of years. According to this line of thinking, the Earth should have already been colonized, or at least visited. But no convincing evidence of this exists. Furthermore, no confirmed signs of intelligence elsewhere have been spotted, either in our galaxy or the more than 80 billion other galaxies of the observable universe. Hence Fermi's question, "Where is everybody?"
"Where is everybody?" Possible Explanations as explained on Wikipedia
Can be one or many "tyrannical super moderators" may send and use messengers to form cults (religions) and impede progress of other civilizations for many reasons. In a more modern setting, this is practiced on less advanced civilizations/countries on Earth. The advanced CIV may empower a rebel group so that they may be strong enough to take out a developing society that will enable them to control their own resources or ally with nations in the region creating pacts and forming larger alliances.It is the nature of intelligent life to destroy others?
Another possibility is that an intelligent species beyond a certain point of technological capability will destroy other intelligence as it appears, as is exemplified by the theorised extermination of Neanderthals by early humans. The idea that something, or someone, is destroying intelligent life in the universe has been well explored in science fiction[Note 5] and scientific literature.[7] A species might undertake such extermination out of expansionist motives, paranoia, or simple aggression. In 1981, cosmologist Edward Harrison argued that such behavior would be an act of prudence: an intelligent species that has overcome its own self-destructive tendencies might view any other species bent on galactic expansion as a kind of virus.[56] It has also been suggested that a successful alien species would be a superpredator, as is Homo sapiens.