PoW is inefficient by design, which SOME cryptocurrencies use. But cryptocurrencies don't need to use PoW. Many already use non PoW systems, and others are going to switch away from PoW (such as ethereum).
> I've been hearing that for years, and it's always six months away.
"hearing" doesn't really mean much since random people can say whatever, but the switch to PoS has never been claimed to be 6 months away until this year. You're probably confused with the beacon chain with successfully launched in 2020.
Not sure this is the right metric, but you can see that the top of the list seem to represent the bulk of all crypto currencies. And if you want to include Tether, it’s apparently based on Bitcoin and Ethereum blockchains.
Bitcoin is proof of work, and is showing no sign of switching to something else. Ethereum is proof of work, and hasn’t switched to proof of stake yet. I mean the tech is ostensibly there, but last I checked the merge still didn’t happen. Even if it was just those two, I would not dare call them "some crypto currencies" like they were marginal. Bitcoin and Ethereum, aren’t marginal, they’re basically the majority all by themselves.
Also, I’m not sure how trustworthy proof of stake actually is. I’ll believe it when Ethereum actually implements it at scale.
