This is where we get the Fermi Paradox from. Even given extremely conservative estimates it seems absurdly unlikely for the number of planets that host intelligent life in the universe to be 1. But also given similar estimations it seems absurdly unlikely that we wouldn’t be able to see any evidence of other intelligent life if it existed. So, clearly our estimates are flawed in some way or another, and we must ask ourselves wherein the flaw(s) lie. Is intelligent life far rarer than we would assume? That’s possible, but it would make use an extreme outlier, which is yet another sign that there may be a flaw in your methodology. Is intelligent life inherently unsustainable? That’s also possible, but a rather depressing thought. Similarly, it could be that interstellar travel is actually just impossible, but we’d like to hope that’s not the answer. Are all the aliens hiding from us for some reason? Maybe, but, like, why?
Another interesting piece of the puzzle is that statistical modeling can be used to demonstrate, pretty much inarguably, that we are more than 90% likely to be among the first 10% of intelligent species to arise in the universe. This, again, marks us as an exceptional case, which is always cause for skepticism about one’s assumptions. One interesting proposal that resolves this problem, while being much more hopeful than the possibility that all life goes extinct before achieving interstellar travel, is that life forms which do achieve interstellar travel are likely to take control of large portions of the universe and prevent other spacefaring life from developing within that territory. In other words, if we assume most aliens would be colonialist, then it becomes more likely that, as intelligent life forms, we would be among the first to have developed, since later in the universe’s life, all the territory in which new intelligent life might develop will have already been colonized. And we would likewise expect not to see aliens, since if they were close enough to see, they would probably already have colonized our system and prevented us from developing within it.
…What were we talking about again?
My theory is in 13 billion years it's unlikely that two intelligent lifeforms would evolve close enough and have the same tech levels in the same timeframe to communicate with each other.
A species evolving at the same rate as us could have evolved 9 billion years ago.
The math suggests it's almost guaranteed life exists elsewhere, intelligent life probably but how intelligent or how far down the tech tree so to speak and how close they are....