The key idea (mentioned here by several threads here) in eschatological religions is that the world (and humans) need to be saved because how bad the world is becoming with humans straying from X (X being one's chosen religion). The problem with the idea is this:-
In any objective measure of human development, humans in general are far better off today than any time in past history (and this is true on a fairly continuous basis since 1900s). One can choose any measure of human development...but if one combines three basic quantifiable metric as:-
1) Is a person who is born living longer and healthier?
2) Is a person being born better educated?
3) Is a person being born has more disposable income to spend?
Then the chart below shows a tale that everywhere and in almost every decade, there has only been a steady increase in all these metrics. (Asia and African nations started growing after decolonization of course).
Historical Index of Human Development
No..you will not be better off if you were born in any past time in history. Indeed given the current trends your future descendants will be far far better off than you. This is no law of physics of course.... rather a testament that despite our enormous follies we are indeed doing better. That is a cause for hope and further dedicated effort.
If you wish to debate this point...please bring forth actual statistically sound data and not anecdotes, opinion pieces or catchy pictures. Thanks.
I wouldn't say that "the world" is on a downward trajectory, although the general feeling that I've discerned overall is that "the west" (however one may define it) is past its peak and in a state of decline.
For America, one can look back to America's industrial and military might during WW2, as well as the unprecedented economic boom which followed, showing measurable economic growth and vast improvements in standard of living far beyond what most people had seen in previous eras. It culminated with the Moon landings from 1969-1972 - even while being involved in a Cold War, a shooting war in Vietnam, and yet still able to provide the high standard of modern living, comfort, and luxury which most Americans had come to expect and enjoy. Most Americans had cars, appliances, electricity in their homes, fixed plumbing, some measure of health insurance, access to public education and many other luxuries and improvements. There were marked improvements in medical care, transportation infrastructure (interstate highways), communications, mass media, electronics (TVs in every home).
In those days, it seemed like America was unstoppable and that there was nothing we could not do or achieve if we put our minds to it.
But at the same time, people also recognized just how highly complex and somewhat precarious it all was, as any one of a thousand different elements could fall out of place and cause the house of cards to come crashing down. One example was the great blackout of 1965. But there were also fears of nuclear war, and people also became more and more aware of the environmental costs of all this industry which provided so much to enhance and improve people's lives. Then there was the energy crisis of 1973-74, which was concurrent with the Watergate scandal and all the revelations about what our government had been up to for the past few decades, as well as facing defeat in Vietnam.
The Vietnam War seemed a major milestone in America. People wondered aloud how we could be so successful in WW2 defeating Germany and Japan, yet we struggled and lost against tiny Vietnam. People saw that as a sign of America's decline. We were also ostensibly kowtowing to Arab oil-producing nations - something America never would have done 50-100 years earlier, when we might have responded more aggressively and confidently.
We suddenly and inexplicably decided to stop going to the Moon, turning the Space Program into more of a satellite repair service than anything else. Where we once expected a future with day trips to the Moon and colonies on Mars - all of that was called off at some point. That, just by itself, would indicate that we reached some sort of plateau where we could not rise higher.
It may not have indicated a downward trajectory, but more a sense of stagnation and a kind of "dead end" where there was no place else to go but down.
Likewise, the energy crisis and subsequent price hikes in energy costs meant that the good old days of cheap gas and gas guzzling cars were over. Real wages leveled off and stagnated. We still had the infrastructure, cars, electronics, TVs, etc. - so it's not as if anything was taken away, but it didn't appear we were moving any further forward. Even the monumental social reforms which were achieved in the 60s and 70s seemed to also level off and stagnate to a large degree.
By that time, the old order exemplified by the "colonial world" was already done and over with. The Postbellum "Jim Crow" laws and other segregationist policies were abolished in the U.S. The KKK, which had peaked in power in the 1920s, was nothing but an empty shell and splintered. The defeat in Vietnam caused U.S. policymakers to embrace new strategies, ostensibly learning from past mistakes (but perhaps not really).
The perceived loosening of morals, the decline in church influence, ending of prayer in school, the rise of sexual hedonism, drug use, crime, etc. - all of this also contributed to perceptions that America is a fading empire, just like the decline and fall of the Roman Empire.
It wasn't a colonial empire or even really any kind of "empire" at all, but more of an underground, unofficial geopolitical "mafia," manifested in puppet/proxy governments friendly to U.S. interests, yet nominally independent and sovereign.
This policy backfired tremendously in places like Iran, which is still considered an enemy and a thorn in the side of the US ruling establishment. The hostage crisis of 1979-81 was another pivotal event which also contributed to perceptions of decline and weakness, which led Americans to believe that Ronald Reagan could be America's savior, as he was a tough, no-nonsense, business-oriented and capitalist-friendly politician who could turn things around and make it "morning in America" again. There was a big push towards "positive thinking" and the "don't worry, be happy" mentality that seemed to counter the more pessimistic, cynical (yet still more realistic) worldview that dominated the 1960s and 70s.
This is the point when America (and much of the world that has been influenced by America) entered a kind of "la-la land" which we've been in ever since, though we're starting to see diminishing returns and serious consequences in terms of the world geopolitical situation and domestic politics within America. In recent years, people have expressed serious misgivings about the direction America and other Western liberal democracies are headed, including a noticeable fear that we could regress and degenerate into some kind of fascist dictatorship.
All in all, your original question, "Is the world on a downward trajectory," is highly complex and hard to really gauge. The world has had its ups and downs.
But all of what we're seeing now is unprecedented, at least in terms of known history. The past 500 years is but a tiny blip in the grand scale of history, but what a "blip" it has been. Much of that time has been spent towards conquering the world, then fighting other conquerors over the spoils, and then working towards economic development and political enlightenment. We no longer believe that slavery is a legitimate form of economic gain. We no longer believe that conquest is a way of gaining land. We no longer believe that burning people at the stake is an effective deterrent to crime. We no longer believe that a person's character or worth is based upon their race or nationality. We have grown and become better educated and rational in our perceptions and worldview.
It's because of this that we can recognize that things are better, but our knowledge and education also tell us that things did not get better by themselves or through some miracle or luck. It has taken a lot of energy, resources, and work to bring all of this about - and the work will never stop.
It's a system requiring constant maintenance, vigilance, planning, engineering, risk management - along with a great degree of faith, work ethic, and ingenuity and adaptability. It also requires cooperation, shared values, and shared objectives. It's in those areas where people might be getting indications of a "breakdown" taking place, and because we are (at least on a cursory level) aware of the underlying problems and all that it takes to maintain and keep an industrial civilization going, there's a sense of uneasiness and fear of what could happen if even the tiniest cog falls out of place. The pandemic was a recent reminder of just how vulnerable we are.
So, basically, this is a long-winded way of saying that I agree with the basic premise behind your arguments here, but that premise requires a great deal of background explanation and a thorough understanding of how we got to this point. My only real criticism here is that I don't believe it tells the whole story to pick a few key metrics demonstrating improvement since 1870 and suggesting that it will continue to get better.
It doesn't mean we're going in a downward trajectory either, but I would liken it to being a passenger on a bus where the driver is not paying attention to the road and driving recklessly. People can see this and become worried, while the driver argues "Well, we haven't crashed yet, have we? Everything's fine! Don't worry, be happy!"