If you think about the truly massive massiveness of the insanely vast universe we live in, it's pretty hard to make the argument that we are the only intelligent lifeforms in said universe. Stephen Hawking famously said that we shouldn't want aliens to visit Earth because they might think just like humans do and do what we did when we started "exploring" our universe (also known as "genocide"). But this assumes that all "intelligent" life is selfish, supremacist, and violent toward things they don't (bother) to understand.
I've often heard the reasoning that "intelligent" life learns how to manipulate their environment so that it better suits the needs of the "intelligent" life. Not long after I first learned that theory, I came up with my own: What if truly intelligent life is life that is smart enough to live its life without manipulating its environment? Dolphins, bonobos and octopuses are all very intelligent beings and even have somewhat human characteristics. The smarts to open a jar (octopuses), the social organization to travel in groups and work together on tasks (dolphins), or even negotiation skills that include homosexual behavior (bonobos). What if the aliens that are out there are just like dolphins or bonobos, or octopuses and might be floating by our planet right now? Maybe they've built a space ship in a way that didn't pollute their home world or strip mine it to its core? What if they didn't even do it by exploiting lesser beings or even members of their own species that were less fortunate? Perhaps they learned to live harmoniously with the other lifeforms and themselves and the natural systems on their planet and only wanted to explore space to see what was out there.
What do you think those aliens would think of us?
Would they be impressed with our thriving economy? Would they think our leaders in government and business were doing everything right? Would they marvel at the plastics and other miscellaneous chemicals that have found their way into every animal on the planet? Would their jaws (assuming they have them) drop at the sight of our incredible weapons of war in action? Would they pat us on the back for how we treat our people of color, our women, or less fortunate?
I suspect that they wouldn't feel very positively about us after gazing upon the humanity that we are.
They'd look at the centuries of war, slavery, and human exploitation, and wonder why it is still happening.
The homelessness, famine and poverty that humans still suffer in the 21st century would be equally challenging for them to understand.
The rich living in mansions would seem to them like their equivalent to medieval castles.
The destruction wrought on the physical bodies and culture of black and brown peoples that continues to this day would probably repulse them.
The way we ignore education and under value not just intelligent people, but the teachers who taught them (and the rest of us), would inspire deep shame and pity from these aliens.
We spend trillions of dollars on invading countries and waging war on those weaker than us, while health threats to all human life, like cancer, heart disease, failing water systems, and more are all but ignored.
They'd squint in disbelief when recognizing what we're afraid of: terrorists, gangs, trans people, homosexual people, people using the wrong gender bathroom, discussion of history, discussion of truth, discussion of the clitoris, discussions of rape, guns, financial/gender/racial inequality, infrastructure, hell, there was a President of the United States who banned broccoli from the White House. It's highly probable that they would find us a petty, shallow, base species.
They'd shake their head (if they have something like a head) at the fact that after 200,000 years of humanity existing in its current biological form and this is still where we are at?
These aliens would likely conclude that not only should they not visit us, but they should stay the hell away from us and make sure we don't ever leave our planet. Of course, they know we're too shallow, and fearful to actually leave our planet without a really, really good reason. We're too focused on our own petty squabbles, truly ancient rules, absurd biases and fears, and overly adaptive bigotry (we'll find any reason to hate or discriminate) to actually make a serious attempt to explore space.
And if they're aliens like Stephen Hawking predicted? They'll kill us anyway, so why not at least try to not seem like shitty space neighbors?