Appreciate the effort in your response!

You're skipping over key details to universalize to all forms of imperialism to what cannot be. The Tendency for the Rate of Profit to Fall is specifically capitalist in nature. Simpler extraction like Roman imperialism didn't have the same mechanisms for export of capital as impelled by capitalist development.

The tendency for the rate of profit to fall is the observation that as labor forms less and less of the price of production, and machinery and tooling forms more and more (which itself is just past labor and raw materials), profit rates decline. The increase in absolute profits comes from selling more, and through expansion. There are limits to domestic production and consumption, so countries that reach this stage in development export capital to more easily and to greater degrees exploit foreign workers, as well as gain new markets.

This, however, is finite, as the rate of profit still falls and you can only expand so much when there are finite countries, labor, and resources. This results in conflict, and eventually fascism, as the super-exploitation of the imperialized countries is forced inward to keep up with absolute profit rates. The domestic working class is soon super-exploited. We see this with the US Empire, presently.

All of what you listed as examples of empire do not have the same fundamental characteristics as imperialism as a stage in capitalism.

I disagree. We haven’t found a stable system yet, so more exploration, discovery, evolution (whichever euphemism you want to insert here) is needed to arrive at something stable for humanity. The alternative is we just accept we get a few generations or tens of generations before society falls and we rinse and repeat.

This is not how society works. We don't "find" systems, they arise and fall based on changes in mode of production and distribution. Liberal democracy came alongside capitalism as a means to perpetuate capitalist rule and facilitate the free flow of capital. Monarchism was largely a function of feudalism, where agrarian production was dominant and serfs paid rent in kind while producing for themselves much of what they used.

Each successive mode of production is found in utero in the previous. Mercantilism and early manufacturing in feudalism, alongside inventions like the steam engine, gave rise to capitalism. Capitalism's progression towards centralization, and vast, inter-connected production gives rise to socialism. Imperialism is the method by which this process is stunted and delayed, but only temporarily, as there are no new markets to saturate and you can only exploit so much while profit rates falter.

No mode of production was "designed." It emerged from what came before. Socialism comes out of the death throes of capitalism just as capitalism emerged from feudalism.

Regarding the US and the "good times," this was for a few reasons.

1. The soviet union dramatically expanded worker rights and social programs, so the US passed the New Deal in order to suppress revolutionary pressure.

2. The US rose as an empire in the early 20th century, and saw none of the devastation the rest of the world saw in World War II. The capitalists used some of the imperialist spoils to essentially "bribe" the working class, while super-exploiting Africa, Latin America, and South America.

China's "good times" are coming off of its own productive capacity and coherent central planning. The US Empire plundered the world for its "good times."

Commodity production simply isn't shifting outside of China, it's that countries like Vietnam (itself a socialist country) are following similar economic models. India is slowly rising, because it isn't a socialist country and is largely still under the thumb of imperialism. China's Belt and Road Initiative is dramatically expanding their ability to sell, and as an export-based economy they can transition more to a consumption-based economy.

China is rapidly increasing farming capacity and energy production, faster than any other country on the planet. They can produce what no other country can keep up with, and are building multilateral ties while the US Empire is being thrown off. The world itself is doing fewer and fewer transactions in USD and more and more in Yuan. The aging population is a problem, but not an insurmountable one, and one that pales in comparison to the US Empire's inevitable demise.

Cuba is a democratic country. It gets labeled "authoritarian" in western media, but the people play a comprehensive role in policy decisions, support their government, and participate in elections. It's a unitary socialist democracy. Further, it's doing as well as it is despite the USSR dissolving 3 decades ago, and gets lots of its trade from China and Vietnam now.

The USSR was not the saturday morning cartoon image you seem to have of it. Life expectancy doubled from the low 30s to the mid 70s. Throughout the soviet bloc, literacy rates jumped from low 30% to 99.9%. Housing was capped at 3% of incomes, wages jumped while working hours lowered, and the working class in general saw the most extreme uplifting in living standards in history (prior to the PRC). The USSR began as a semi-feudal backwater with living standards among the lowest in the world, and became a developed country within decades.

The expulsion of fascists and opportunists from the government was necessary. The famine in the 1930s was not a manufactured one for the purpose of genocide, but caused by weather disaster and wealthy farmers destroying their crops and livestock to resist collectivization. It uplifted national culture while also trying to develop an internationalist culture.

The USSR was by no means an empire. It did not run an economy based on international plunder, but a planned economy focused on satisfying needs. It did not run its economy based on financial domination and extraction.

The USSR did dissolve, but it wasn't because of a faulty economic model. It did spend a good portion of its GDP on keeping parity with the US millitary (to avoid being nuked into oblivion by the US Empire), and this did hurt the economy, but economic growth was still positive up until the end. It was dissolved politically, from the top-down.

All in all, to circle back, it's really difficult to give you a full picture of what I'm talking about without giving several books worth of context. The key point here is that the US Empire is running out of markets to expand to and is turning its exploitation inward, while countries like China have a clear and bright future, thanks to moving on from economies dominated by private property and the profit motive to one based on public ownership and intentional planning.