The most successful currencies can be reliably counted on to maintain their value. Through the backing of a central bank, the fiat currencies (currencies issues by a central government, not backed by a commodity) receive a value based on the public trust in that central bank/government. In cases where that trust diminished to zero, the actual value of the materials involved in the production of banknotes and coins have a value (albeit tiny). Therefore, government-backed currencies can theoretically, never be valueless.
Bitcoin is a decentralized currency. It is not backed by any central bank. Therefore, it has no value and is not linked to public confidence in a monetary system. Without value or the backing of a central bank, Bitcoin is intrinsically worthless.
Many asset classes have no intrinsic value yet still command high and relatively stable prices. The global diamond industry is a glaring example of this. Diamonds have no intrinsic value, benefit, or function. Their entire value is dependent on supply and public demand. Yet diamonds are a relatively stable asset class. This is because, in economics, an item holds value for two reasons: utility or scarcity. Exactly like diamonds, Bitcoin has value because of its scarcity. There is not an infinite supply of bitcoin. The cryptocurrency has a cap of 21 million Bitcoins. In fact, this makes Bitcoin more valuable than many precious metals and minerals. Because it is man-made, there is no possibility of a hidden Bitcoin treasure trove being discovered and flooding the market.
[P1] Bitcoin is valueless. [P2] Therefore, its value is entirely dependent on public demand. [P3] If that demand falls to zero, the currency can be worthless. [P4] Without intrinsic value, Bitcoin will always be riskier and more volatile than fiat currencies. [P5] Therefore, Bitcoin is not the future.
Rejecting the premises
[Rejecting P2] The price of Bitcoin is not solely dependent on demand. It is also dependent on scarcity. [Rejecting P4] Bitcoin's scarcity gives it value.