How so? Advancement comes from your own researches and innovations, not from US sanction of certain chips that China is not fabricating now. China will advance further because it plan to produce those chips sooner or later. There will be initial hurdles, but these will not be insurmountable because there is no lack of talents and money when this quest becomes the highest priority. We are not talking about India or even Japan here.
The business interest of certain Chinese companies might be hit in the short term, but it can be mitigated given China's own large domestic market. China is first to recover from Covid-19 while most major countries are still being held back by the epidemic. China is now embarking on dual track or circulation economy. Local consumption is being stimulated with a host of measures..
The short sighted move by Washington will eventually hasten China's technological advancement. When China can produce those high end chips (or close to the level) domestically , the days of these US Companies and equipment suppliers will be numbered.
I do agree with your conclusion that the sanctions might hasten China's tech advancement and spinoff the domestic chips industry. However, I don't agree with your assessment that the sanctions wouldn't affect China's tech advancement in many areas.
For example, Huawei could still design 3nm chips but it couldn't produce them as the door of TSMC is shut. In the short term, those Huawei engineers can rely upon their expertise to advance the 3nm design. However, in the long run, without the mass production and feedback from customers, Huawei's advancement would stall. In the contrary, Qualcomm would be benefit as it would get more orders from Xiaomi, Vivo, and Oppo and demanding a better price. More profits, more market share and more R&D funding would enhance Qualcomm competitiveness.
There would be many examples of Huawei and major Chinese tech companies spending their time and resources to design and redesign their products so that the American component can be taken out. Many companies would be forced to redesign their products at lower specifications due to the sanctions.
In conclusion, the sanctions would force the advancement of the semiconductor equipment makers and material providers. It would also spinoff the development of EDA and many software. The sanctions also hindered the development of advanced and design chips. If SMIC is sanctioned, then it would spend many resources to just maintain its production by switching out American equipment and material. It would greatly affect SMIC's advancement of 7nm or 5nm development.