Your point is noted but I don't think this is an apples to apples comparison. American policy makers have a point. The semiconductor supply chain covers so many STEM fields of expertise that in theory, no individual country should be able to take it all on alone while still being at the cutting edge. I don't think anybody assumes Russia is capable of creating a competitive semiconductor industry, supply chain and all, but everybody assumes it would have no problems with autos, petrochemicals, nuclear plants, military hardware, etc. Building a complete semiconductor supply chain, near the leading edge, is on a different level.
That's what American policy makers are counting on. They believe their tech accomplishments cannot be surpassed without their cooperation. They're gambling that if they can withhold their most advanced technologies and all of their geniuses, that they will be able to stop China dead in its tracks because China alone would never be able to completely catch up, let alone surpass them. I think they're totally focused on China's relatively backward laser interferometers, TEM, O/CD-SEM and other extreme precision machinery to limit their semiconductor advances. This would in turn restrict China's AI, CPU, GPU and Cloud advances, which in turn would restrict their scientific/technological advances in general. That is the only logic that would explain these otherwise self-defeating tech sanctions.
Why do so many here think the tech sanctions will fail? Imo, I think the West are suffering some sort of psychosis that gradually built up through generations of mass brainwashing to the point the bulk of their populations and leadership can no longer accept reality. You see glimmers of rationality here and there, but the at the end of the day, the mass brainwashing works even though everybody knows about fake news. This is my thesis and would explain why their policy makers keep kicking themselves in the balls despite the pain.