This is a good step. Russia has tried manufacturing chips in the past, completely failing[0] to produce even fairly rudimentary 28nm CPUs. Cutting off their access to first-world manufacturers would kneecap their ability to scale up their current hardware, and force them to use homemade hardware that's 5-10 years behind the curve of what's readily available today. Technology is only a portion of this battle, but the move to cut them off is undeniably a smart one.
[0] https://www.tomshardware.com/news/russias-biggest-bank-tests...