Never gonna happen. Cash has no intrinsic value exccept maybe for use in fire / toiler paper. GPUs while currently inflated in price will always find enough value. Their price might go down 50-75% but never 99%
That's the meaning of intrinsic calor - the device can do what it can do, regardless of market conditions. Today it has the value of fifty teraflops, and tomorrow it still does, unless it breaks. However, intrinsic value cannot be measured in dollars.
And yet we're talking about electronics here, they don't have sentimental value and just because compute capacity is unused there are no guarantees that it will be used, even at a per unit cost approaching €0.
I'm sure that farmers during the Great Depression were also consoling themselves with the "intrisinsic caloric value" of their corn.
As I said, the intrinsic value of a GPU is not measured in €. In fact, the lower the sale price gets, the better a deal it is, not worse - you get the same intrinsic value for less extrinsic cost.
There are also intrinsic costs, mostly power consumption.
Food calories are cheaper to convert into something useful. It's not like GPUs, once bought for peanuts, turn into perpetual motion machines. They need power, cooling, a whole infrastructure built around them.
GPUs would have taken the world by storm already in the roughly 30 years since they've been around.
Even for GenAI it's likely ASICs take over at some point if we really care about performance.