Obviously if Bitcoin goes tits-up it will not be more stable than gold. There seems to be a non-trivial probability Bitcoin will go tits-up from shitty governance alone, but barring that it seems to me that Bitcoin has the potential to be far more stable than gold. Access to gold is dependent on a large amount of geopolitical factors that could all change at any time, as well as mineral extraction technology that is getting better all the time.
Extrapolating far enough, we'll never find an asteroid that's miraculously made almost entirely out of Bitcoin.
I'm curious as to whether your viewpoint is the same for all cryptocurrency or just Bitcoin.