There must be some kind of barrier that prevents the rise of intelligent, self-aware, technologically advanced, space-colonizing civilizations. Speculation of

There must be some kind of barrier that prevents the rise of intelligent, self-aware, technologically advanced, space-colonizing civilizations. Speculation of this sort is interesting but I think it's important to realize it's extremely hypothetical. It can't help but have many hidden assumption and fail to say many "unknown unknowns". One key unstated assumption is that a interstellar space faring civilization could be achieved through technological advancement in short -or-medium order on earth. That a "sci-fi" world is just around the corner. Our current society has indeed been based on constantly, even exponentially increasing technology. But there's no visible way to sustain that exponential growth to the scale of the stars. Indeed, our society's growth is increasingly, visibly unsustainable and our ability to counter our destructive tendencies isn't making progress. So maybe what has to replace our unsustainable trajectory is a society with no technological progress. You could this as "maybe the 'great filter' lies ahead of us" or maybe you could say the image of both the Fermi Paradox and science fiction is based on a belief that Earth's future has a strong potential, a strong tendency to look like the previous 300 years of the increasingly technological expansion of European capitalist society over the globe. And that belief, for good or ill, may be not at all justified. And the thing is that such "filtering" might imply that a given technological species fails, just that it reaches stability and isn't part of this a stellar colonization effort.