Very interesting points; there is a scientific clarity in your analysis. But, I would like to add a point: the reality is that the production is in global scale now, the production has no borders, races, nationalities, but the capital has its local interests. The working class is a global class, while bourgeoisie is a local class. But since the bourgeoisie is the dominant class, it makes the working class divided. Like the role of black bourgeoisie in the disguising class struggle under the hood of racial issues. I think this small piece of text helps make my point a little bit clear: http://www.theinternationalism.org/2020/07/return-to-marx.ht...
A lot of work is moving abroad without becoming imports. US companies own significant chunks of the services and R&D workforce the world over. Even in production, it's not uncommon for a US company to buy a factory rather than importing goods produced in that factory.
I didn't mean the point is the imports. The fact is that US is loosing his share of world GDP for decades, and new powers like China are rising. It is just like the decline of British empire at the late 19th and early 20th century and rise of new powers like US, Germany, Japan. We are witnessing the same phenomenon that Lenin called unequal development of capitalism in the imperialist stage. We would also see the same tensions and wars that we saw in the first half of 20th century.
Global GDP is irrelevant for US workers, the value of US exports has grown even as wages stagnated. At some point it just stops being about how much value is produced and becomes a question of how much value is captured.
If a factory produces 10x as many goods with the same number of workers the work those people are doing has increased in value. But, their unlikely to see a 10x wage increase.