By those measures, you may as well say Bitcoin is "useful" for Chinese millionaires to evade exchange controls whereas before they were forced to have Rolexes up their arms on the plane from Shanghai. Or in supporting the graphics card market. And none of those applications for gold explain its price movements when, for example, Russia invaded Ukraine. That the other two instruments were as you say used in speculation means they also had no intrinsic worth in their price, no?

I dunno, I feel like crypto is just an exaggerated version of most other asset classes, not at all uniquely terrible in its own right.