The Ethereum upgrade should be happening in the next year (unless it gets postponed again, and if so no one will be surprised). Part of the upgrade will basically end all Ethereum mining with GPUs. With Ethereum being the most profitable GPU mined crypo currency, as well as the most common, it stands to reason that the demand for GPUs will drop significantly. In fact it seems as if this is already beginning to happen. And while there are cryptos one can mine with video cards, none are as profitable as Ethereum. Also, with the price of all cyrpto crashing has taken a toll on mining profitability, reducing GPU demand.