If you’re buying gold you’re not purely depending on finding another sucker to buy your gold. You can sell it to any one of the countless manufacturers or jewelry makers using it every day. If the price crashed too much, these would probably just increase their inventory of gold in anticipation of a future price increase, which would itself drive up price. If the price stayed low they can lower prices on the goods they’re making, increasing demand for gold, stabilizing the price.

That’s why cryptocurrency is not digital gold. There are no such mechanism setting a fundamental floor for how low the price can go.