I walked into a computer store last night. There were shelves full of CPUs and SSDs and HDDs, and buying several of them at once would have no one batting an eye. Yet there was a policy: only 1 graphics card per customer per month, and that applies solely to graphics cards (and prebuilt computers containing graphics cards).

In other words, there is visibly a shortage of graphics cards that is not affecting any other components. That strongly suggests that there is something driving demand for graphics cards that is not driving demand for other key components of computers, which are available in sufficient supply. And the list of things that extra demand could be coming from is rather short indeed.