I low-key love the fact that sci-fi has so conditioned us to expect to be hanging out with a bunch of cool space aliens, that legitimate, actual scientists keep proposing the most bizarre, three-blunts-into-the-rotation "theories" to explain the fact we're not.
Some of my favourites include:
Zoo Theory: What if there are loads of aliens out there, but they're not talking to us because of the Prime Directive from Star Trek? (Or because they're doing experiments on us???)
Dark Forest Theory: What if there are loads of aliens out there, but they all hate us and each other so they're all just waiting with a shotgun pointed at the door, ready to open fire on anything that moves?
Planetarium Theory: What if there's at least one alien with mastery over light and matter that's just making it seem to us that the universe is empty to us as, like, a joke?
Berserker Theory: What if there were loads of aliens, but one of them made infinite killer robots that murdered everyone and are coming for us next?!!
Like, the universe is at least 13,700,000,000 years old and 46,000,000,000 light years big. We have had the ability to transmit and receive signals for, what, 100 years, and our signals have so far travelled 200 light years?
The fact is biological life almost certainly has, does, or will develop elsewhere in the universe, and it's not impossible that a tiny amount of it has, does, or will develop in a way that we would understand as "intelligent". But, like, we're realistically never going to know because of the scale of the things involved.
So I'm proposing my own hypothesis. I call it the "Fool in a Field" hypothesis. It goes like this:
Humanity is a guy standing in the middle of a field at midnight. It's pitch black, he can't move, and he's been standing there for ages. He's just had the thought to swing his arms. He swings one of his arms, once, and does not hit another person. "Oh no!" He says. "Robots have killed them all!"