The ongoing decline of the West was always very predictable, and not because of some inherent law of the universe that says all civilizations must fall after their rise or any such thing. After all, before there were religions, there were no religions. And before there were sophisticated languages, there were no sophisticated languages.
Humans are capable of constructing social technologies that make up the institutions which form the bedrock of a functional society. Nothing technically prevents a civilization (long-running, complex society) from existing indefinitely if its institutions are very well maintained (invention, repair, deletion etc as appropriate).
It is possible to have a civilization which never dies. Peaks and troughs are what are probably impossible to prevent.
The decline of the West is primarily happening because the West lacks a rigorously-thought-about and well-defined civilizational goal. This is what contemporarily allows for the corruption of culture and the pursuit of fake, ruinous goals.
You can ask any Westerner today what the point of their personal existence is, and what their society seeks to achieve, and they will have no cogent answers for you.
Thankfully, you can look at the actions of both the individuals and their governments to determine their implicit pursuits: liberalism and consumerism.
If you live in the West today, you will ('must', actually) be liberated from all traditional constraints and have no genuine aspirations except for the consumption of things of all forms, natural or artificial, through all of your human senses, and preferably, all at the same time.
Mindless consumption is the highest good.
This of course predictably leads to the degeneration of culture.
Traditions do not exist for no reason. Some of them do become outdated due to better scientific understanding or technological innovation, but lots of them (especially the moral ones) are definitely vital.
Absolute liberation from tradition is guaranteed to result in disaster for an obvious reason: you are jettisoning vital knowledge encoded in culture which has helped the society survive until your own time.
And that is exactly what Western liberalism is obsessed with doing. And it is not only obsessed with doing that, it is totally committed to exporting it to other regions of the world.
There will be no comeback for the West like some people think. Why? Because the same liberalism eating it from the inside out prevents the rise of reformers who can set the system right. It is like if a disease were attacking a body's own immune system.
How ever could competent reformers rise from within if existing institutions believe that everyone is equal and freedom is its own end?
The classic way to solve this problem and how I assume it is solved in Medicine is for an external agent to be introduced to aid the ailing immune system. In the case of the West, no one who understands its problems and has the ability to help will raise a finger to do anything.
Because it is not in their interest. What happens to be in their interest is in fact further, maybe even faster degeneration of the West.
No one will help the West because Westerners have been very very arrogant for a long time while having little to show for their annoying cockiness.
Every single Westerner is exceedingly arrogant and always has been. Lots of people (usually right-wingers) believe in an inherent greatness of the 'West'. They believe in an inherent superiority of "the Western man". Some of this obviously follows from how the West has led technological development and was able to colonize a lot of the rest of the world in the past couple of centuries.
And in the case that they do not believe in an inherent God-given superiority, they believe in the supremacy of supposed "liberal Western values" which are by how humans are unquestionably supposed to live, and they are happy imposing these 'values' on other people outside of the West. Of course they never really think of the means of bringing these ideas to other people around the world as imposition.
Tell you what.... everyone is tired of all of the bullshit. The center will collapse, as will the rest of the West.
To reiterate: the primary reason that the West will collapse is the lack of a rigorous and concrete civilizational goal. Every single sign of dysfunction which you can point to is downstream of this fundamental problem: an inability to define concretely who a member of the in-group is, who to and how to run society, the boneheaded and obsessive worship of liberalism as an end of its own etc
So it happens that the West will die for very avoidable reasons and the lesson to learn for other people from other parts of the world is to seek to understand why, and to avoid making the same mistakes.