One of the interesting things about the last 3 years - or really almost the last 25 years prior to this - is watching a long, slow decline. It is interesting because it is the sort of thing one reads about in history books happening to other societies at other times, but one never really considers that it will happen in one's own life.
Part of that is, for lack of a better phrase, dumb luck: someone that lived in late 4rd to early 5th Century A.D. Britain did not see much change at all; someone born in the early to mid 5th Century saw an entire way of life, if not completely disappearing, at well on its way to vanishing over the horizon.
In some ways historians have a leg up on examining these sorts of things: having seen one societal decline, one knows what to look for in others. In some cases, as in Sherlock Holmes, the historian sees not only what is going on but what is not going on - noticing the the dog that did not bark and what that is indicative of.
I suspect - were one to look for such things - that those in power at all times and in all places, try to slow the decline as much as they can. After all, they are the ones that are in the position to benefit the least when the structures that give their lives power, wealth, and meaning get swept away. At the same time, it is fair to say that those agitating for A Brave New World are not always the winners either: as multiple revolutions attest to, human nature and circumstances are fickle things and leaders of revolutions are just as likely to get swept away as anyone else.
The argument against the general decline of the West - at least here and now - is made somewhat complicated by the fact that we are - seemingly - at the pinnacle of human experience. We are moving slowly out into space again, repeatedly. We have every sort of technology imaginable to meet not only our needs, but our wants and desires. We get the world delivered to our home and can see the world from our home. How, in the midst of such obvious comfort, material wealth, and technological advancement, can we be talking about any sort of decline in the vein of the Western or Eastern Roman Empire, Edo Japan, or Tsarist Russia?
I eschew pointing to specific events in general, as 1) Events and trends are subject to the interpretation of the individual and thus present points of disagreement instead of discussion; and 2) Specific events may or may not be indicative of future outcomes - sometimes things that I would think would accelerate any sort of downturn are ripples in the pond while others which are seemingly minor have great impact. The novel thing about history of course: you can only really understand it looking back even as it is lived forward.
I suppose where I would point to is a sense of the future.
What, in the world of analysis and media and punditry, is the vision of the future which is being offered? If this - the current timeframe - is the pinnacle of 3,000 years of human advancement and history, what do we have to look forward to? The reality is that, at least for myself, I have heard no-one propose the sort of future that sounds anything like where we would want to live.
Yes, of course, space travel is always "the option", and maybe we will get there someday (for those that are interested in such things, The Silicon Graybeard has a daily and weekly round up of such things). But it will not be like the books and movies; both expense and physics are against us.
The visions that are being provided by multiple groups does not sound enchanting: smaller everything, less everything, packed tighter and tighter into larger and larger cities which are more dependent than ever on resources from everywhere, a giant maw devouring food, energy, consumer goods, water - and returning only waste to the surrounding areas.
Were this an industrial plant in a pristine environment, we would rightly call "foul" on such a plan and actions. Because it meets various agendas and beliefs, we call it "acceptable".
(Note 1: To be clear, all sides in the current sociopolitical milieu, or at least 89% of them, are to blame. There is no "Red' or "Blue" here, to use the American version. Either they have some vision of the above, or simply no vision at all other than "the opposite", without having any real definition of what the opposite is. At best, it is "more of the same" - the same, of course, being ill defined.)
(Note 2: It does make wonder if this lack of vision has contributed to the overall rising of the gaming industry, which has now outstripped the movie industry in terms of popularity. I wonder if, given the fact that no vision is offered for this world and its future, people are quite willing to go find other worlds and places to explore, adventure in, and live in. It has the benefit of at least being entertaining.)
Societies and civilizations exist and survive because ultimately the individual somehow benefits from them, although arguably not all equally. Remove that benefit - give individuals nothing but the mere traces of benefit and no ability to invest in their own future or better themselves - and the individual's reason for investing in the society and civilization disappears.
In the later Western Roman Empire (3rd Century), the provinces of Gaul were wracked by internal civil conflict. The Bacaudae, a combination of "local free peasants, runaway slaves, and deserters from the legions, who were trying to resist the ruthless labor exploitation of the late Roman proto-feudal colonius manorial systems and military systems, and all manner of punitive laws and levies in the marginal corners of the empire." (Source). They were initially crushed, but continued to re-appear the next two hundred years in various corners of the Empire.
Give people enough reason to not invest in the society or civilization and it will simply disappear to become only a memory and reminder of past greatness, buried in books for the future historians to read and marvel at.