It's backed by mathematics instead of a country. That doesn't make it better or worse, just different, and diversity is generally what people want in their portfolio.
That is actually one of the strongest arguments, to my mind, for why some variant of a cryptocurrency will survive as a store of value. Gold kind of "organically" found its way into value almost precisely because it is backed by the physical laws of nature. Cryptocurrencies went up a level to be backed by the laws of mathematics.
Bitcoin is also a Schelling point.
Making gold has always been the holy grail of chemistry. It's only valuable because chemistry says you can't make it easily.