Who is "society"? Users of cryptocurrencies obviously find them useful, or hope they will be in future. The alternative to cryptocurrency and blockchain contracts are global alliances that make trading in dollars easy in all important markets and enforce contracts across jurisdictions. Billions of people who are not part of these alliances are left out and the rest are reliant on US/Europe remaining leading superpowe…
"Users of cryptocurrencies obviously find them useful, or hope they will be in future" Do they hope they'll be useful in the future because they think they're great technology that everyone should benefit from... or do they want them to be useful because they bought in early and want to get rich?
We get a lot of obviously not-ready-for-prime-time stuff hitting production because it's too lucrative (see any number of DAO and smart-contract schemes that imploded), and there's a systemic allergy to input from the outside world as to what normal consumers want (things like reversability and systemic backstops), because the current system appeals to speculators.
I'd see the case for "useful in the future" if there were more efforts to answer the no-breakthrough-tech-required "faster horses" problems people have with mainstream finance. FedNow is coming in months and will give me settlement in minutes for pennies, and likely very solid legal backing. This is faster horses. Crypto might offer similar settlement speeds, but I understand it depends on the particular chain I choose, and to an extent, how much I'm willing to pay to push the transaction through. I'd also wonder how reliably the courts will accept a crypto paper trail if there's ever a dispute on a payment. (Not necessarily because the trail is bogus, but simply because it's not a well-established precedent of who and what can be trusted)