nVidia choose to use Samsung's 8mm node and obviously the yields are not good or the large die itself is very demanding and they just can't get enough of these cards manufactured. The nVidia shareholder statement shows about 6% of their sales went to crypto dedicated channels. There's probably more cards in the hands of narcissistic Youtube "influencers" than went to mining.

Stupid behavior on AMD's part saying there would be plenty of supply for the new RX line also didn't help.

Both launches look like absolute failures on the part of their logistics and deployment teams. The engineers can only do so much.