@akissthroughtheglass at this point I'm making it a new post so I'm not derailing OP's post too much :P
I will admit that I have oversimplified the possible outcomes for the United States in particular. (In my defense, I am ill with the flu right now and kinda missed the nuance there.) There are possible futures in which the United States collapses and yet capitalism goes on, its center moved to some other metropole.
But the end of capitalism itself can only be apocalyptic or communist.
And yes, that is a social theory, regardless of whether you have scorn for it. It's a social theory built and expanded upon by highly educated and intelligent people for a couple centuries now. It's not messianic--that implies waiting for an individual messianic figure--but I think what you really mean is probably closer to millenarian. Wikipedia's definition for the word works here:
the belief held by a religious, social, or political group or movement in a coming fundamental transformation of society, after which "all things will be changed".
And yes, absolutely, this is a millenarian way of looking at the world. That doesn't mean it's incorrect, though. Sometimes society transforms!
Not necessarily for the better. For instance, your point:
Dominant social orders tend to default to their easiest alternatives, not the perfect idealized social solution to the global situation.
I'm not sure exactly what you mean by "easiest," but I'm going to assume you meant that in a water-flows-downhill sort of way. Correct me if I'm wrong! If I'm not, we're on the same page about that. I agree. The process by which the new social order is produced within the context of the old social order, and eventually overthrows that old social order, is an example of dialectics, and dialectics follows a path of logical progression. There were dozens of classes with their own interests in medieval Europe, but only the bourgeoisie emerged victorious in the new colonial world, because their relationship to production and property resolved contradictions of the old order and gave them many advantages. The Aztec Empire was incredibly complex, but it fell to Spanish rule because of Spain's many advantages over it. I don't think it's reasonable to say that these large historical processes could've gone that much differently.
So why am I advocating for the inevitability of an "idealized social solution?" Well, for one thing, I don't think the process of getting there will be at all idealized. It'll be ugly and violent and the world will take time to recover. For another thing, I believe that it will occur because I can see that capitalism is unsustainable in the long run and the proletariat's relationship to production resolves the contradictions of the old social order and gives them many advantages. (Simplifying a lot here but there's no helping it, all I have is a tumblr post's worth of space.) You may disagree, but it is a rational position formed on the basis of evidence, not "idealism."
After all, global civilization has unlocked the powers necessary to kill itself, and that could happen before communism wins. I really fucking hope not, but it seems possible.
The white Christian nationalists will say it's about Jesus. The Eastern Europeans and Chinese who associate communism with oppression will continue to do so. The capitalists will keep going to work and managing their asset portfolios. Do you genuinely think Hindu nationalists are going to experience 140 degree heat and decide Marx has the answers?
Those are idealist movements, and your argument is idealist. Idealism isn't a doomed adherence to utopia. Idealism is the belief that history turns on ideals. I am a materialist; I know history turns on material conditions, and ideas follow from there. I don't expect the entire world to sing the praises of Our Prophet Marx. I expect that a global oppressed class will, through its material interests and proper organizing, rise up against an oppressor class that has had the run of the roost for a long damn time.
But to be honest they probably will cite Marx. There's a lot of communists among the oppressed peoples of the world. You mentioned India--are you familiar with the Naxalites? Hindu Nationalism is only the current ruling ideology. No place is a monolith.
Don't stop at the first decent looking idea you encounter. Keep searching even if you think you're right. Communist or no, you haven't found the answer to everything quite yet.
Goddess spare me. Communism is not "the first decent looking idea [I] encouter[ed]." I was raised as a liberal, which involves way more magical thinking and idealism, and it took a long time to un-learn that.
And the proper response to not having figured out everything isn't to sit around and read until I do. It's to learn, act, grow, and find a path forwards for my own liberation and the liberation of others. I've been at this shit for a hot minute and have gone through many changes in my thinking. The important part is doing something about it.
If you would like to learn more, I highly recommend Dialectical and Historical Materialism by Joseph Stalin. For the most part I don't like Stalin, but this particular little pamphlet by him is a good summary of some damn near objectively true things which your analysis could sorely benefit from.