With TCP/IP, or packet switching, they did have an idea that it will be useful, but noone could imagine how popular it's going to be. With crypto, it seems the opposite, I'm afraid.
Noone needs a use case for a Raspberry Pi, or a Raspberry Pi Pico (the latter, many would say, borders on being useless with other, cheaper and/or more complete platforms being available). But I can just buy one, and tinker with it and voila. I don't need a use case to run a Z80 retro emulator on a Pico, I can just do it on my own, without any "industry" deciding which type of emulators should the investors have.
Why "crypto" needs a use case is exactly because people insist it's money, and had to be acquired with money.
While it was all P2P, and you could get whole bitcoins for fun, it were different times. Nowadays, you can't mine any meaningful amount of it unless you invest in thousands, or you buy them with money or credit card. And it's starting to be either illegal in some countries or in a custodial wallet, going poof when the company goes bankrupt.
Did you say 'over'? Nothing is over until we decide it is! Was it over when the Germans bombed Pearl Harbor? Hell no! It ain't over now, 'cause when the goin' gets tough, the tough get goin'. Who's with me? Let's go! Come on!...
(returning): What the f--k happened to the crypto I used to know? Where's the spirit? Where's the guts, huh? This could be the greatest night of our lives, but you're gonna let it be the worst. 'Ooh, we're afraid to go with you, crypto, we might get in trouble.' (shouting) Well, just kiss my ass from now on! Not me! I'm not gonna take this. Coinbase, he's a dead man! Celsius, dead! Ethereum...