How did you verify they were stunningly inaccurate?
A lot you can verify just by looking at our strategic decisions in the moment vs. how things turn out later and internal communications get declassified. We didn't understand that the Sino-Soviet split had happened until decades later, and still thought that China and Russia formed a united communist bloc well into the 80s. A number of people still think of China as communist, which isn't true at all.
I'm actually seeking out information contrary to my experience here - I would love to see stories where U.S. intelligence agencies were completely on the mark but were ignored. But my knowledge base so far is that intelligence agencies are as vulnerable to human cognitive biases as the general public, and frequently get basic facts wrong.
Probably because it's evolution into a mafia state has been much slower. President Xi has been slowly accumulating power for 15 years. Since Mao power was purposefully kept defuse, and while corruption has been rampant at least since the free market reforms, it was of a different kind and in some respects served to maintain competing power centers.
I think that Chinese corruption is very different in character from Russian corruption. Russian corruption stems from a sort of hyper-individualism and a belief that you need to take what you can get while you can get it, because somebody else will if you don't. Chinese corruption, however, often starts from the belief that the family is the fundamental unit of social organization, over the self, country, and God. Nepotism ("filial piety") is deeply ingrained in Chinese culture, and isn't really considered a bad thing. Beyond the family, there's the web of social relationships and obligations ("guanxi") through which business is conducted, but Chinese people usually don't buy appeals to higher organizing principles like patriotism or salvation. There's an odd relationship to the concept of nationhood, as well: here, you're American if you have a piece of paper proving American citizenship, while for a Chinese person you are Chinese if you are ethnically Chinese, regardless of where you're located or which passport you carry. (This is a source of occasional tension for Chinese-Americans: when interacting with another Chinese person, their immediate assumption is that you are Chinese too - "You're Chinese, why don't you X?" - while most of us are more likely to say "Actually, I'm American.")
One thing that both China and Russia share is a weak rule of law, though. Laws are routinely bent in both of these countries if it suits the interest of a powerful person or furthers a relationship. America is headed in the wrong direction in this regard - and IMHO the words of the current president don't help here - but there's still a default assumption here that the law is the law, and that we're all equal before it. This is a fiction, but it's a powerful fiction that has led to a lot of prosperity for America, and would probably lead to much suffering if people stopped believing it.
I've known a lot of Singaporeans and their concept of 'kiasu' (https://en.wikipedia.org/wiki/Kiasu) is very similar, though I'm not sure if the origin of the behaviour is from China.
I get the sense that the Russian impulse also extends toward power, though. Chinese people generally do not have an urge to tell other people what to do. Even when they're at the top of a hierarchy, commands are usually couched in language of it being for the greater good, or to ensure social harmony, or that it's simply right and natural. And this is different from the strategic form of dissembling that is common among powerful Americans, where they tell a broad populace that it's for their own good while secretly admitting to themselves that it's mostly for their personal benefit. Chinese people really don't make the distinction - it just never occurs to them that others' interests might not be aligned with their own. And I feel like that's very different from the Russian impulse to seize power when they have a chance - Russians are keenly aware of when there are powerful people whose interests do not align with their own, and then try to act quickly to ensure that they get what they need before someone else does.
Come to think of it, a lot of Cold War (and present) foreign policy could be explained by these cultural differences. The U.S. impulse to shore up potential strategic options if there is a challenge (but not make aggressive moves themselves) is interpreted as a threat by Russians who assume that American defensive moves must be a prelude to seizing power/territory/wealth. Meanwhile, the Chinese are off in East Asia milking every bit of free stuff out of their newly capitalist economy, which is interpreted as a threat by both Americans and Russians but is actually just them grabbing free stuff while possible, and they don't understand why this could possibly be construed as offensive. The U.S. response of containment (through Hong Kong, Singapore, the Philippines, Taiwan, etc.) is perceived as promoting disharmony among largely ethnic Chinese people, though, which is an affront to their culture.
This is not true. See e.g. the 13 August 1969 Presidential briefing:
https://www.cia.gov/library/readingroom/docs/DOC_0005976931....
Choice quotes:
"The potential for war between them clearly exists."
"A climate of high tension, marked by periodic border clashes, is likely."
"Peking, which appears to view the USSR as its most immediate enemy, will face stiff competition from the Soviets in attempting to expand its influence in Asia."
The USA actually held discussions with the USSR to bomb China's nuclear missile facilities. Moreover, this knowledge aiding in reaching rapprochement with China in 1972.
A related comment in that vein is people the west often don't get that people other places correctly see their corrupt semi-authoritarian governments as their best real option.
On the other hand I have read a declassified early '80s CIA report (too lazy to search for the link right now) that nominated two relatively young communist apparatchiks as potentially having the chance to replace Romanian dictator Ceausescu. One of them was Ion Iliescu, who in fact did just that in December 1989, after the Romanian "Revolution" (the other one was Virgil Trofin[1], who had been demoted to running a State agriculture farm where he suffered a sudden and mysterious death in 1984). As a matter of fact just as they were about to get shot Elena Ceausescu reproached to her husband: "I told you that we should have killed Iliescu". Not sure if the powers that be in the States acted or not on this piece of good and accurate CIA intel.