Bitcoin mining hasn't relied on graphics cards in years. SHA2 calculations are highly amenable to ASIC speedups, so ASICs took over Bitcoin mining pretty early in its history.

I didn’t downvote you, but your point does not necessarily invalidate the point you responded to. The whale of cryptocurrencies more or less props up all of the smaller coins, which are relying on GPUs and even SSDs/HDDs in mining. It goes down, they could lose enough of value to suffer their own runaway effects, and crashes will make PC gaming and computing overall much more affordable.

That other cryptocurrencies would depreciate in the event of Bitcoin's dissapearance is a highly debateable point.