I think a tendency for intelligent life to destroy itself would make it more rare than it already is, but doesn’t do enough to account for the unlikelihood of never encountering it. Once a species is spread across more than one planet, I would think it would be very unlikely for an extinction event to wipe all of it out before some survivors can bounce back. So all you would need is one or more civilizations beating the odds up to that point to become basically unstoppable.
Also, intelligent life might frequently kill itself off, but that doesn’t mean intelligence is a disadvantage to long term survival. The vast majority of unintelligent species also go extinct. It’s more that reaching stability is quite hard, with or without intelligence.
This is one possible answer to the Fermi paradox.
I think a tendency for intelligent life to destroy itself would make it more rare than it already is, but doesn’t do enough to account for the unlikelihood of never encountering it. Once a species is spread across more than one planet, I would think it would be very unlikely for an extinction event to wipe all of it out before some survivors can bounce back. So all you would need is one or more civilizations beating the odds up to that point to become basically unstoppable.
Also, intelligent life might frequently kill itself off, but that doesn’t mean intelligence is a disadvantage to long term survival. The vast majority of unintelligent species also go extinct. It’s more that reaching stability is quite hard, with or without intelligence.