You're mixing up "capitalism" and "production/industrialization." The two are not one and the same.

China and India are recapitalizing to good effect. Russia is recapitalizing

China and Russia are if anything, doing the exact opposite of what you claim; while Russia may be structurally and politically capitalist (and while China retains its market socialism, which is another spiel in and of itself) the developments ongoing in both are not the capitalization (privatization, financialization) of their economies, but rather the submission of capital to the interests of the state and the public good (in Russia's case, its national security) and towards actual production.

What part of China's cracking down on corruption and speculation (engaging in the controlled demolition of its real estate markets for instance) and engaging in even further state-led development sounds like "capitalization" to you? What part of Russia's own return to 5-year plans, of its reindustrialization (of which a large part is the MIC- which by and large is state enterprise, not private), of the cracking down on the corruption and influence of the oligarchs (now that the west has so helpfully neutered them), and the return to domestic production and development rather than financial instruments and other grifts geared towards the transfer of wealth to the west sounds like "re-capitalization," or rather, "further capitalization?" (Considering that Russia still is decidedly capitalist).

Meanwhile, the UK is just six banks in a trench coat and their economy is disintegrating underneath them.

Because the real "economy," or rather everything people associate with and can tangibly interact with, was never truly capital (though capital certainly has considerable correlation, as a system built over it). The British economy is disintegrating because the "capital" you seem to assume Britain is lacking in, is actually present in overabundance (and was developed relative to the size and influence of the former empire and what plunder it could obtain). Britain is literally choking on, and drowning in its capital (inflation), while it's bourgeoisie, to preserve the value of their capital (which has no inherent value in its own right), bleed the British society and true economy further and further dry, through their endless pursuits of their bottom lines, through their rentier behavior (landlordism, monopolistic behaviors/oligopolies, and through extracting what could be described as "rent" from the state in the forms of corporate welfare- particularly the MIC- regulatory capture and the maintaining of captive markets, and copious tax breaks). And of course, they also preserve their value of their capital, by taking it out of the sinking ship- by moving it into actual tangible assets, exchanging it for the currencies/capital of nations whose economies are not going into freefall, and which are not ridiculously overpriced (capitalized) bubbles ripe to burst.

Saudi Arabia is trying to build out capital in excess of its oil drilling and desalination systems

Saudi Arabia is another nation absolutely swimming in capital accumulated from its oil revenues; they have no need of ""building"" capital, they have no lack of it. What the Saudis are trying to do, is convert said capital into tangible assets and production- ie. actual value (of which capital is just an approximation and floating measurement of). They built what capital they have, off of such (natural) assets (obviously, oil), and are trying to prepare themselves for the transition past it, as well as develop actual productive forces outside of oil extraction (as that is the actual wealth of the nation- not capital, which is a fickle, unstable, and abstract measure of value).

I could go on further, but basically- capital =/= production. And Americans work, sure (a immense amount of it "bullshit jobs," as from the sounds of it you're aware). But the expansion of US capital and imperialism across the globe, the network of American "capitalization," if you will- has literally priced the American working class out of existence (they still exist obviously- but it's a miserable and withering thing).

The USD is kept artificially overvalued, allowing the US (particularly it's corporations, but also the citizenry that have increasingly moved to "bullshit" largely unproductive jobs) inordinate purchasing power, something the US state and corporations abuse the utter hell out of .

US labor, being paid in the USD, is artificially overvalued- which is to say, it is prohibitively expensive and uncompetitive, and what manufacturing, agriculture, etc. exists is generally heavily subsidized so as to keep the gears of empire turning. Goods and services within the US are artificially overvalued (overpriced) due to the "capitalization" of the economy as well- everything in the US is "capitalized" to hell and back (and it is no more productive for it, oftentimes less). Tuition, healthcare, housing, food, consumer goods, etc... there are layers upon layers of "capitalization" in the US, of course not least of all through the "capitalization" of immense consumer and state debt (line goes up). None of this is "competitive" or "appropriately valued-" rather the opposite- and thus even marshalling the productive forces of the nation and moving past all the "capitalization" is a cartoonishly expensive and arduous hurdle.

I could go on further, but I'd simply recommend looking up the talks on economics on YT (or their writings, etc) by professors Michael Hudson and Richard Wolff, as well as the Geopolitical Economy Report among others for more information to set you on the right path.