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.