I don't think it is irrevocably broken. I for one think there is still a lot of potential in cryptocurrencies and public blockchains. I believe a credibly neutral store of value not in the control of any nation state is something that benefits the world.
Why can't we celebrate what is good and try to fix what is bad?
I think the issue I have is the crypto folk haven't wanted to fix any of it -- with the rare exception being ethereum moving to PoS. A lot of the "fixes" would break the "features".
Cryptocurrency communities are aggressively hostile to improvement. Every chance to make the ecosystem better is met with pushback. It's funny you bring up PoS, because how much energy was spent (pun absolutely intended) by the Ethereum community fighting that change?
It doesn't make sense to celebrate the good and fix the bad in cryptocurrency because a nontrivial portion of its userbase actively wants it to keep its terrible qualities and will fight anyone tooth-and-nail that tries to fix its problems. It's exhausting to even have conversations about what parts of the ecosystem need improvement.
I mean, this project is still using Bitcoin, right? So clearly we're not going to fix the bad parts of cryptocurrency, because if y'all in the cryto-community were willing to fix any of the bad parts, Bitcoin of all the implementations wouldn't still somehow inexplicably be your most popular coin. Cryptocurrency is a system with a lot flaws, but its biggest problem that gets in the way of it turning into something useful is that its community that has internalized those flaws as strengths.
And honestly, that's the charitable interpretation. The less charitable interpretation is that there are a lot of bad actors in cryptocurrency communities that aren't even interested in building something useful in the first place, they're purely interested in furthering whatever scam they're working on at the moment. How much of the PoS fight was about genuine academic disagreement about centralization, and how much of that "disagreement" was just a cloak over "I think I have pretty good thing going on with this GPU farm and how dare you mess with that"?