I'm increasingly convinced that what I call "naive fact-checking" misses the forest for the trees.
Facts matter, yes. But a false narrative, even, or especially where constructed at least in part on true facts, is vastly more significant.
A characteristic of virtually all Big Lie Narratives is that they contain, often major, nuggets of truth. But the arrangement of narrative amonst these, and eventual insertion of false (or at the very least, unverifiable) facts, eventually proves these out.
A classic example I've run across is "It's All a Rich Man's Lie", an epic 3h 40m YouTube conspiracy yarn which, at least in its first hour or so, sticks largely to the domain of underlying truths: yes, there are "secret societies" at Ivy League schools, yes, many major US industrial firms maintained operations or divisions in Nazi Germany, etc. But no, actually, Kennedy's "Secret Society" speech (mentioned about 20 minutes in) was not about the Yale Skull & Bones group, but instead about the Soviet Union, and its practice of leveraging unflattering or inconvenient reporting from the US itself against the US.
(The question of whether or not Kennedy was right in asking for self-restraint on this basis is a matter for another discussion.)
Often the individual elements and false narrative become apparent by pulling back ever so slightly from the presented story, and looking at the greater context of facts offered. A few paragraphs of surrounding context from the Kennedy speech ("catnip for conspiracy nuts" according to one source) make painfully clear that its topic is not what the conspiracy nuts would make it to be.
The fact that such checking is expensive and takes time makes the fabricators' job all that much easier, and the debunkers' harder.
Another interesting case is the "J.P. Morgan Bankers' Manifesto" hoax, by one Thomas W. Gilruth, first published in 1892, and still making the rounds on social media over 120 years later. I'd run across it by way of an meme whose message appealed to me, though thinking it might be too good to be true, I dug deeper.
To my knowledge, this is the most substantial debunking of the Gilruth hoax ever published:
https://old.reddit.com/r/dredmorbius/comments/39w8u4/jp_morg...