I read a lot of fantasy and science fiction. I cannot say how many times I’ve run across a passage like this in a fantasy novel:
…and the Night’s Watch had a proud tradition of protecting the King for over 2,000 years,
or this from science fiction:
…a galaxy spanning civilization that had endured over 5,000 years…
Here’s the thing: we humans can’t state with much certainty what happened to us a couple of thousand years ago, and generalizing, we can’t say much about what happened earlier than that with any specificity. There is nothing to suggest that anything we produce, from structures, to works of art, to political institutions, to societies, has much chance of surviving more than a few hundred years at best. And yet epic fantasy and science fiction are replete with examples of passages like the above, with authors imagining societies that have persisted statically for millennium only to be disrupted by the events depicted in the novels.
I get that I’m nitpicking forms which by their nature are intended to entertain us by challenging our sense of how things work, but it just doesn’t scan, especially in fantasy. If you could spend some time explaining to me how a society remained stuck as a feudal state for 6,000 years (and even be aware of the passage of that many years), or at least offer some clues as to why, or even wave your hands about and blame it on ‘magic,’ great, maybe I can look past it, and sometimes authors even try to do this. Most of the time though, they don’t (and as far as I can recall anyway, even when they try I haven’t come close to buying it). They want to imagine some grand civilization on the precipice of change and imbue this with a sense of drama and poignancy implied by just how long these institutions have stood, but instead it just comes across as bombastic and silly.
TL;DR: Fantasy and Science fiction authors: please read some history and get a more realistic sense of scale for human endeavors. ‘Fantasy’ is not the same as ‘impossible.’