If price of gold was according to its "actual value", it wouldn't be $3300/oz right now. Nor would anyone hold it if they expected its price to ever get down to such "actual value". Bitcoin really isn't any different in that regard - it has value because people are willing to trade it. Although it does have practical uses, as well - black markets, for example.

The actual value of bitcoin is that you can use it to buy illegal counter-cultural things like drugs, fake IDs, etc. Except you can't, because more anonymous cryptocurrencies were invented and the markets migrated to those. Now Bitcoin is mostly used for more "serious", "wall-streety" crimes, like bypassing international sanctions. Either one can hold up the value of an investment asset.