> The idea that China doesn't have the people and organization to copy things other countries make is the opposite of Chinese Exceptionalism. It is the belief that the Chinese are uniquely incapable of engineering work. This is obviously not true.
Which broadly leads to two conclusions:
They can't do it. If they could they would. If you could invest and create your own Nvidia, ASML, TSMC, &c. you would do that especially if you are China due to its stated goals and actions it takes that we can all see toward those goals.
They can do it and so selling them the chips doesn't matter other than helping to speed up their ability to do it, so we don't want to sell them the chips and thus speed up their capabilities.
But your viewpoint also holds true for the United States and Europe. Anything China can do we can also do, otherwise you're just supposing Chinese Exceptionalism.
Suppose you want to build something that requires technical knowledge (a GPU, a fighter jet, ...). You have engineers, but they don't yet know how to build it.
If no one on earth has ever built this thing, you need to consider the possibility that it can't be done at a cost you can pay. Perhaps it violates some law of physics, or it can't be manufactured without knowing some chemistry/physics that we are 100+ years from discovering.
If a company in some other country is already building this thing, you can be sure it is possible to build it. That is a critical piece of information! It means you don't need to discover (much) new physics. It means you can buy/steal a working copy and look at it to learn about it. It means there are engineers you can hire/spy on to understand their design process. It means you can more easily convince a bank/government to fund development, as they have proof your goals are achievable.
Inventing a thing is much harder than inventing a clone of a thing. The idea that China doesn't have the people and organization to copy things other countries make is the opposite of Chinese Exceptionalism. It is the belief that the Chinese are uniquely incapable of engineering work. This is obviously not true.