What makes you think, 2,000 years from now, our ancestors will look back and a) remember what happened accurately, and b) learn from it?
I can imagine someone in the future saying "No man, that wasn't humanity's fault... the earth just goes through natural cycles. Or maybe it was just the sun."
In short: I think you're denying our contemporary and historical reality if you think that, in the future, we'll do any differently.
Edit: As an aside, I want you to reflect, for a moment, on our ability to understand human society even just 500 years back. Even at a time with decent written records, there's still entire disciplines focused on trying to understand how those people worked and lived, and enormous amounts of disagreement on the same.
Now imagine we fast forward, say, 2,000 years after we've destroyed modern society and started to rebuild in earnest. An enormous amount of information about who we are is now locked up in optical, magnetic, and solid state storage, and the technology to read that information will be destroyed right along with the rest of us. Much of the rest is stored on paper that doesn't have the long-term archival properties of something like vellum.
Why do you think our ancestors will understand us any better than we understand people in the middle ages?
Personally, I think "it's just inevitable that all civilizations die from ecological collapse" takes some of the emotional frisson out of the doom and gloom as well; if it's just that inevitable, you can't really blame anyone, can you? If it's inevitable, it isn't really "fossil fuel's" fault (after all it is likely that many civilizations never even had fossil fuels, or lacked an oxygenated environment or similar that makes combusting them so easy), or careless use of farm land, or anything else... it's just the inevitable workings of the impersonal universe.
As with many other putative answers to the Fermi paradox, I don't think this one is powerful enough to explain it.
Absolutely, which is why I said "an answer" as opposed to "the answer".
We know all this stuff is possible and it is unlikely that everyone that knows something will die, just as it is unlikely that all print resources will be taken away.
Cars and cell phone towers will still likely exist. Televisions, radios, computers. The remains of power plants will stand.
We'll continue to wash our hands after shitting because we won't lose germ theory.
Sorry, but there is no going back to the stone age. At worst, the tech of today becomes the goal of humanity after our numbers rebuild.
I.e. if man/animal labor is more effective than crude machines, then societies never make mass investment into crude machines and don't prepare large numbers of people working with said machines, so there's no stimulus that might ever reach fancy machines that might be actually useful. We'd have the same fate as the medieval Chinese society, which invented lots of nifty tech centuries before Europe, but didn't go beyond that to the industrial revolution for social reasons until the progress elsewhere forced the social reasons to change.