The stock shortages for cards like RX 6800 and RTX 3060 Ti / 3070, and sure the 3080/3090 are unprecedented. But for the first series equipped with GDD6 graphic memory, the main reasoning could be just that, GDDR6 graphics memory.

The French-based Cowcotland mentions that worldwide shortages of gddr6 memory are (partly) to blame. Coincidentally we last week learned that Nvidia- CFO Colette Kress stated that the shortage of Ampere video cards is not only caused by wafer shortages, but also by 'insufficient substrates and other components'.

We should note that cards like RTX 3080 and 3090 have GDDR6X graphics memory, and these are even worse to find in stores. Prices of older graphics cards such as the RTX 2000 and RX 5000 series are now steadily rising. It could take many weeks for the gddr6 shortage to be resolved. The availability of the affected models could thus return to normal in February, provided there are no other component shortages by then. 

Poor availability of RX 6800 (XT) and RTX 3060 Ti and 3070 would be due shortage of GDDR6 chips