Yes, those supply chain problems that the companies blamed when they increased the prices a lot during the mining boom and that then suddenly didn't stop them from lowering the prices a ton once that demand dried up. Color me skeptical. There has also always been a large second hand market, but plenty of people only want new cards.
The problem with all of these explanations is that we can just tell they are nonsense because the prices are simply not consistent with any of these explanations, which should give a certain pattern. For example, I can get a 6600 for 270 euros, but a 6600 XT for 360 euros. Yet these should have pretty much the same BOM cost. Same chip, same memory. The entire card is the same except the binning. So common sense is that the 90 euro difference is not because the 6600 XT costs more to make, but is purely more profit. And quite excessive too. They could easily sell it for 300 euro or so.
The 3060 has 4 GB more of memory, which should cost less than 40 euros. The chip is a little bigger than the N32 chip, but should be cheaper per mm2, so it probably isn't more expensive. So common sense says that they could sell the 3060 for 270+40 = 310 euros and have no worse profit margin than AMD has for the 6600. Yet the cheapest is 383 euros. So either you have to believe that a company with more volume that could logically work more efficiently, is actually less efficient, or you can believe that the extra 73 euros are profit. I believe the latter.
Companies are not gods. Nvidia has already proven that they make mistakes like with the 4080 12 GB. I don't get all these fantasies that these companies are some godlike entities that never make misjudgements.