It isn’t, as your link shows, no other successful use other than cryptocurrencies or things explicitly tied to cryptocurrencies exist. There’s theoretical uses, sure, but nothing practical. Ipso facto it’s just for cryptocurrencies.
Yes but this is the kind of thing PCs are uniquely better at so it kinda feels like a waste of time. I prefer my collaborative efforts to go towards something which enrich the commons. That’s just my take however you do you.