And assets are worth whatever other people are willing to pay for it. My friend sold a digital-only World of Warcraft character to someone for over $2000 once, and for the longest time there was a sub-industry based around buildings of employees playing the game to get and sell World of Warcraft gold, so much so that it got its own term of 'goldfarming'.
Crypto has value because other people are willing to pay the asking price for it. If that ever becomes not the case, then it's no longer an asset. Could that ever happen? Possibly, and I'd say definitely for certain coins. But now that this idea exists in the world of programmable tokens that can be exchanged quickly and cheaply and decentralized public ledgers, I don't think it's ever going away, not totally.
Something that you want me to use to buy things with should not be so volatile that it goes from pizza to luxury home in less than ten years years. If I had some bitcoin "lost in the cushions of my couch"from that era I would be a rich man today.
Crypto currency has become a massive misnomer. To that end I'm not sure WHAT it is any more because if it isn't stable as a currency and it doesn't have intrinsic value then what good is it?