Cute but wrong comment.
Bitcoin mining is getting something out - the unallocated millions of bitcoin still in limbo. We all know where this bitcoin is and mining is how you get it.
Nor is "useful", the least bit convincing. Gold has very little societal use - its value rests almost entirely on belief of its value. The same can be said for gemstones, art, stamps or any other collectible.
The cryptocurrencies aren't unique or limited - the 5000+ crypto in existence, with one coming out pretty much every week or several days, if proof of that. Nor am I the least bit convinced that even bitcoin has much of a future given its enormous electricity overhead.
But most importantly - there is a basic premise wrong with any attempts to talk about fiat vs. crypto: the law.
Fiat is mandated by law as payment for any debts, public or private. Crypto is not.
Fiat - particularly bank accounts - have all manner of regulatory apparatus around them. Crypto does not.
But, some of this can change and a little has changed already. The existence of CUSIP accounts at major financial institutions to hold bitcoin is one prominent example. CUSIP are custodial protected accounts - traditionally used for stocks and bonds but now expanded to include crypto.
Un-nuanced views on crypto are all wrong. I still think of crypto as nerd art - and bitcoin as (relatively) Rembrandt vs. shitcoins as street corner portraits, but that's just a personal view.