Science

Honestly I never truly understood the appeal of cryptocurrency in general.

If you want to make an anonymous deal, cold hard cash gets the job done and doesn't have nearly as poor of an environmental impact. I guess if you really want to make sure online purchases are anonymous then it can be hard to do that with cash, but unless you are buying something blatantly illegal that shouldn't be too large of a concern (at least if you are in a first world country). The whole "decentralized" currency argument also falls pretty flat when some of the top used cryptocurrencies are not decentralized (Tether, Usd Coin).

Cryptocurrency feels less like an innovation to fit a need, and more like somebody created something cool as a concept and tried to figure out a use case after the fact.