The actual interesting and novel thing about crypto-coins was solving the "trust problem" of a distributed ledger. But this solution, to be honest, is quite clumsy: PoW. But nobody ever found a better solution until now. Any other proposal is kind of centralized somewhere.
The question that needs to be asked is now "Do we really want, or even need, a fully decentralized 'value moving system'"?
In a world where you could ultimately trust someone else the answer would be clearly "no".
But when there is on thing to learn about humans than it's "never ever trust someone ultimately as you're going to be scammed by those people eventually". Just look at what government do around the globe…
As long as this fact doesn't change (and it won't change until we create a new species of intelligent beings, better than us) there will be room for something like BitCoin. And as those are distributed systems there even doesn't need to be any agreement on that point.
And then there is what we do know about what happens in practice:
https://www.cnbc.com/2019/03/22/majority-of-bitcoin-trading-...
https://www.theregister.com/2018/11/30/blockchain_study_find...
"We found a proliferation of press releases, white papers, and persuasively written articles," Burg et al wrote on Thursday. "However, we found no documentation or evidence of the results blockchain was purported to have achieved in these claims. We also did not find lessons learned or practical insights, as are available for other technologies in development."
Amusingly enough the darknet use of crypto may only be possible because of the Ponzi-beginnings. Criminals are unlikely to accept Pokémons as currency until after they see others doing it.