There’s no paradox, there’s just people plugging in guesses for numbers which almost certainly wildly exaggerate the likelihood of intelligent life arising.
It took evolution 75% of its available runtime to produce intelligent life (which itself was likely the product of a particular runaway process which has happened exactly once on this planet), with a number of near-misses that would probably stagger the imagination if we knew about them all (indeed, the few near-misses we do know about -do- stagger the imagination, and lead people to believe religion might have something to it after all).
There’s no paradox, there’s just people plugging in guesses for numbers which almost certainly wildly exaggerate the likelihood of intelligent life arising.
It took evolution 75% of its available runtime to produce intelligent life (which itself was likely the product of a particular runaway process which has happened exactly once on this planet), with a number of near-misses that would probably stagger the imagination if we knew about them all (indeed, the few near-misses we do know about -do- stagger the imagination, and lead people to believe religion might have something to it after all).
Or that intelligence existing for a long time necessarily implies interstellar spread.