I'm reminded of Eisenhower's quote "Plans are worthless, but planning is everything." You can't convince a million men to row across the channel by just saying "we're going to kill Hitler." You have to provide them with a string of proposals that are not likely to succeed by themselves, like jumping out of airplanes, sending thousands of bombers to Germany, splitting the atom in a bomb, in order for the mountainous proposition of invading Germany to end the war seem not just possible but probable.
This seems to me to help explain 3 closely related, essentially fictional, phenomenons: futurism, conspiracy theories, and suspension of disbelief in narrative fiction.
Futurism, as mentioned, becomes more palatable as details are added. AI overlords seem dubious, but spin a tale of white coated researchers, misguided investments, out of control corporations, and it suddenly becomes imaginable.
Conspiracy theories need a rabbit hole to guide victims down. Carefully constructed stories nab readers by beginning with dubious but plausible claims ("this is a first person account of Epstein's limo driver"), followed by possible but improbable ("I was then transferred to Utah to dispose of bodies for the Romney family's out of control nephew"), followed by the ludicrous ("I personally witnessed Roger Stone raising bodies from the dead on Epstein's private island"). The final claim made in isolation would be rejected by anyone still standing at the rabbit hole's edge. We need to add many improbable details for the final point to stick.
Finally, fiction in general is constructed of unlikely or impossible scenarios that we somehow are able to integrate into our identity or understanding of the outside world. We can think of every line and paragraph as a conjunction to make the final theme, like love always triumphs or good overcomes evil, not only palatable but absorbing the reader with a feeling of conviction.