Personally I find it hard to understand why so many people (and even scientists) are so obsessed about speculating about alien life. I think there is probably a loose connection to religion in that, maybe, people just want something to be "out there". I think that finding out about non-alien life, i.e. the life we find on this planet are causing to get extinct at a breath-taking rate, would be much more rewarding.

I am happy with us obviously not knowing an answer to this right now. Given the current knowledge, I would say that the most likely explanation is a combination of these:

1. the universe is vast and there may be life elsewhere, but the universe is vast and we cannot reach each other. Warp drives are impossible and just wet dreams.
2. most life does not advance much beyond the "intelligence" humans have developed so far (for various reasons) and humans probably won't advance much farther either before they get extinct (climate chance anyone?)

Every year the number of species that get forever lost on earth is probably in the 1000s, most of them directly or indirectly because of human activity. I think we should worry about life on earth more than life somewhere else in the vast universe.

Hmmm... maybe #4 ... they're here and they hide because they're waiting for us to evolve. If i had it made living under the ocean then why would I mess around with the idiots that live on land? This is so hard to understand... I say I think it's #4, but I'm almost certain we'll be their workers at their beckon call....

Develop a method,to communicate that exceeds the speed of light. Quantum entangled matter has been done by the Chinese.

I just saw a cartoon that is apt for this question. I couldn't download it so made a photo. Lets see how this works.

I think the fermi parradox is flawed because it assumes aliens havent visited earth, and obvious mistake.

Nice video, learned something too. Pondering this very question for over 50, answer? IDK...

I used to say because any advanced species would dismiss, or simply be afraid of, us as 'a suicidal species'.

This exact same idea was covered in the Humanist Magazine. "New Atheism, Meet Existential Risk Studies" I am both fascinated and distraught at this idea.

[thehumanist.com]

A recent article in “The Atlantic Monthly” had a lot to say about this [theatlantic.com]

For a civilization that has learned to survive across cosmic timescales, humanity’s entire existence would be but a single moment in a long, bright dawn. And no civilization could last tens of millions of years without learning to live in peace internally. Human beings have already created weapons that put our entire species at risk

The Milky Way has been habitable for billions of years. Anyone we make contact with will almost certainly be older, and perhaps wiser.
Moreover, the night sky contains no evidence that older civilizations treat expansion as a first principle

First contact would be trickier still if we encountered a postbiological artificial intelligence that had taken control of its planet. Its worldview might be doubly alien. It might not feel empathy, which is not an essential feature of intelligence but instead an emotion installed by a particular evolutionary history and culture. The logic behind its actions could be beyond the powers of the human imagination. It might have transformed its entire planet into a supercomputer, and, according to a trio of Oxford researchers, it might find the current cosmos too warm for truly long-term, energy-efficient computing. It might cloak itself from observation, and power down into a dreamless sleep lasting hundreds of millions of years, until such time when the universe has expanded and cooled to a temperature that allows for many more epochs of computing.

Secular humanists won’t be spared a sobering intellectual reckoning with first contact. Copernicus removed Earth from the center of the universe, and Darwin yanked humans down into the muck with the rest of the animal kingdom. But even within this framework, human beings have continued to regard ourselves as nature’s pinnacle. We have continued treating “lower” creatures with great cruelty. We have marveled that existence itself was authored in such a way as to generate, from the simplest materials and axioms, beings like us. We have flattered ourselves that we are, in the words of Carl Sagan, “the universe’s way of knowing itself.” These are secular ways of saying we are made in the image of God.

If you were an extraterrestrial would You want to interact with US on any level?

I like the old joke - "There is proof of intelligent life in the universe already! It's - they haven't called us yet " I would hate it if aliens showed by acting like Joel Osteen. That thought gives me the creeps. Oh no, not the evangelizing aliens again - just go back into space, OK?

I think the most likely answer has two sides to it. Space is massive and we are too unsophisticated to detect life.