Where are all the aliens? Fermi Paradox explained

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The question we have been asking ourselves over and over is are we alone in the universe and if we aren't then where are all the aliens . The universe is big and its expanding on a daily basis at a rate beyond our imagination. There are about 2 trillion galaxies in the observable universe. Each of this galaxies have nearly 100 billion stars . Our own galaxy the milky way has 400 billion with 0.1% of the stars have planets and some have habitable planets on them. Am not saying their is life in them but are found in an area called the goldilock planetsthis means that they have a capacity to sustain life. So with such a high probability then why is their no life ever discovered

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This lead to what is called the Fermi Paradox. This was coined by a physicist Enrico Fermi, The apparent contradiction between the lack of evidence and high probability estimates for the existence of extraterrestrial civilizations. Fermi as he observe the marvelous beauty of the universe could help wonder if we are the only civilization in the universe and could not understand that after the years since the formation of the universe that we could be only civilization in the observable universe and asked the question "where is everybody"

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Fermi realized that any civilization with a modest amount of rocket technology and an immodest amount of imperial incentive could rapidly colonize the entire Galaxy. Within ten million years, every star system could be brought under the wing of empire. Ten million years may sound long, but in fact it's quite short compared with the age of the Galaxy, which is roughly ten thousand million years. Colonization of the Milky Way should be a quick exercise.
So what Fermi immediately realized was that the aliens have had more than enough time to pepper the Galaxy with their presence. But looking around, he didn't see any clear indication that they're out and about.

This has cause a lot of theories to come from scientist at SETI (Search for Extra Terrestial Intelligence) to try to explain the Fermi Paradox. in 1964 by the Soviet Russian astronomer Nikolai Kardashev proposed a method of measuring an advanced civilization's level of technological advancement. The scale is only theoretical and in terms of an actual civilization highly speculative; however, it puts energy consumption of an entire civilization in a cosmic perspective. It was called The Kardashev scale. Using this scale the came with the following theories of why we dont see aliens by the amount of energy the use

A Type I Civilization has the ability to use all of the energy on their planet. We’re not quite a Type I Civilization, but we’re close (Carl Sagan created a formula for this scale which puts us at a Type 0.7 Civilization).

A Type II Civilization can harness all of the energy of their host star (like they do it in star wars). Our feeble Type I brains can hardly imagine how someone would do this, but we’ve tried our best, imagining things like a Dyson Sphere.

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A Type III Civilization has the ability to access power comparable to that of the entire Milky Way galaxy. the natural thought is that they’d probably have mastered inter-stellar travel by now, possibly even colonizing the entire galaxy.
One hypothesis as to how galactic colonization could happen is by creating machinery that can travel to other planets, spend 500 years or so self-replicating using the raw materials on their new planet, and then send two replicas off to do the same thing. Even without traveling anywhere near the speed of light, this process would colonize the whole galaxy in 3.75 million years, a relative blink of an eye when talking in the scale of billions of years:

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