It's a little more complicated. No matter how stupid American officials and businesses may be, they were nevertheless smart enough not to give all the key technologies to the Chinese, but to place them in Taiwan and around China. In China, there are only assembly plants that are made in Taiwan, the USA and a number of other countries.
All maintenance of key items of ASML equipment is also done exclusively by ASML employees. Of course, there is a problem with espionage, and some employees are always rats for money, but they are identified.
If China actually had complete documentation of all the key technologies of the West and had the human capital to copy. He would have done it already. But they can't.
In the USSR, by 1949 they were able to copy an atomic bomb using drawings stolen in the USA, by quickly creating the necessary production facilities and with the availability of high-quality human capital immediately after the Second World War. And they were the first to make thermonuclear bomb and the first to fly into space. But this was a brief moment based on a layer of quality, but "old school" human capital (which was taught by the tsarist professors and teachers with a very good level of university training, who almost all knew 3-4 foreign languages - English, German, French and Latin), which, from purely from sharply growing patriotic considerations (especially after the Second World War), despite the massive persecution of the intelligentsia before 1941 and after WW2 by totalitarian goverment, helped the Stalinist regime, contrary to the logic of the moment, to advance sharply technologically.
I wonder what would have happened to the USSR if there had not been a World War II, with the increase in totalitarian practices and the complete degradation of patriotism? Most likely it collapsed by the 60s, early 70s, almost certainly. It was the victory in World War II and the powerful growth of patriotism and enthusiasm of people in a destroyed country that contributed to the fact that even the intelligentsia, who understood the whole essence of this terrible totalitarian machine, began to help this system recover. And in vain they helped them.
Can the current Chinese totalitarians, by attacking Taiwan, sharply increase the growth of patriotism and temporarily reduce the resistance of the intelligentsia to the totalitarian machine and even start advanced productive activity for the benefit of the klepcrats? I doubt.
At a minimum, for this it is necessary that the United States attack China, so that the war for the Chinese population becomes patriotically domestic, and not an obvious act of aggression against another state, so that propaganda does not scream loudly there.
Let's remember history - Stalin understood perfectly well that it would be more profitable to attack Hitler first in 1940-1941, but he waited patiently, knowing that even against the backdrop of losses, the war for his country would become a just domestic war, and not external aggression. He was wise(or his closest advisors), although bloodthirsty.
Putin and his kleptocrats are not like that, he is just a pathetic shadow of Stalin (having destroyed the country to the ground in terms of industrial, scientific and social potential during 25 years of rule - in fact, they are national traitors, although they brand others for this and throw them into prison, kill those who points out the obvious facts that it is Putin's vertical that are the traitors) and his associates, but he has nuclear weapons, the largest arsenal in the world, despite an almost 10-fold reduction since the times of the USSR, so he gets away with almost everything, no matter what he does, and the United States plays along with him in this, despite all the fictitious "sanctions" (moreover, publicly declaring that they are against Putin's vertical, and not against the common people, but everything is exactly the opposite - Putin's kleptocrats and oligarchs travel freely in the West and having fun, buying assets as before, just with more complex workarounds and increased bribes to officials in Europe and the USA), obviously after 2 years of the bloody show in Ukraine.
But by the 1970s, new personnel began to come to the USSR in science and engineering. who did not know 3-4 languages and could not even read Western documentation in the original for the purpose of self-education en masse, although formally they had a "higher education" according to the new standards of the USSR (here is an interesting fact - if the United States really begins to lag behind in science and progress (it really doesn't yet), is it time for its youth to learn Chinese?), and even more so correctly and clearly copy Western technologies normally (moreover, when not there was a real private interest in this, except for extremely low wages, and not a share in business and private ownership of the means of production), because higher education after the Second World War, as the Russian old professors wrote, sharply degraded precisely because the highest power kleptocrats They were terrified of the expansion of a well-educated "middle class" with knowledge of several foreign languages, which almost all high school students in Tsarist Russia knew and who were able to read in the original not only technical literature, but also the political press and the works of Western writers, which could lead to a new revolution already against them. Thus, over several generations of students, they brought the situation with higher education in the USSR to a completely deplorable level. I emphasize on average, although there have always been rare stars, they do not determine the overall strength of the country in scientific and technical progress - but a wide layer of extremely educated intelligentsia that flourished in the USA and was forgotten in the USSR. As a result, the United States, by pumping up the "middle class" with credit and a generally comfortable social environment, secured a powerful scientific and technological lead by the 1980s. And the USSR is mired in a swamp. And the envy of the "middle class" of the USSR towards the standard of living and freedoms in the West only grew along with the growth of communications. Everything was decided in the 80s. The USSR collapsed, and besides, the local middle-level nomenklatura was also interested in the emergence of private ownership of the means of production, and therefore also contributed to the collapse of the USSR.
In China/Russian Federation there is now formally private ownership (although in reality it is fictitious even in the USA) of the means of production and the right to accumulate capital. But these are all also totalitarian countries. Russia remained a totalitarian country in the 90s.
It was not for nothing that I wrote above about the forerunner that led the USSR to socio-economic collapse in the context of what is now happening in China. The new regimes in Russia and China are smarter in terms of manipulating the crowd of ordinary residents (and control technologies have reached a new, previously unimaginable level) and formally (only formally) create the appearance of the existence of law and private property, but they are also infinitely stupid in plan to create a comfortable socio-economic climate for the emergence of that very fruitful layer of the "middle class", which contributed to the rapid separation from other countries of the United States and its closest allies in the 20th century against the backdrop of the Cold War.
Therefore, their collapse is a foregone conclusion, despite the fact that the United States and its allies are themselves on a spiral of collapse and are rapidly losing that same productive and creative "middle class" along with a drop in the level of both school and higher education. This level is still enough to train Chinese students to copy already invented technologies or for them to join the ranks of scientists in the USA/Europe, but not enough to create advanced productive strata capable of new discoveries and the next revolution in science and technology. The bet on "AI" will end in fiasco in the next 15-20 years, because... will not solve the growing systemic problems in the West.
There is no good end for humanity here anymore. Young people entering adulthood will have to choose the best of evils and, of course, woe to future retirees. They are all being robbed and robbed by the growth of inflation turning into hyperinflation through the depreciation of personal savings on a massive scale. This has always been the case and this will be the case this time, when the ruling kleptocracies and populist politicians serving their interests are trying to evade responsibility by once again destroying the correct fabric of society and the economy, thanks to the connivance of the majority of the stupid population, which at the moment is an unjust redistribution of the results of the work of previous generations may even be profitable at the suggestion of these kleptocrats.