All economies are built on some combination of trust, fakery, coercion and hard work. The underlying rationale of a currency backed by "real material" is that it can be trusted to last. It can be trusted more than any government. Governments can fall quickly.

Bitcoin hasn't proven itself to the degree of gold. It doesn't necessarily have to, though. It just has to look _better_ than alternatives, within some useful timeframe of economic activity(i.e. more than a year or two, but probably less than a century). And, as the original author wrote, it might fall apart suddenly, but then it is basically the same risk as a government-backed currency.