If you are focusing on the bad side of a tech, AI could do way worse than crypto. I mean, the most evil thing you can do with crypto is merely taking away money from people.
You could argue that most of these theoretical consequences have nothing to do with the technologies themselves, but that's true of almost all software technology. Even a potentially devastating piece of malware is, in a vacuum, just some bytes floating in space, with no inherent meaning until someone chooses to execute it. Most discussions about morals in programming and computer science either ignore or gloss over this part as if it is already answered, but it probably matters.
There's some arbitrary dividing line where you decide when the blame lies with the operator(s) vs the technology itself. In practice, I think it's more useful to look at it in terms of who's executing the code instead of who's writing it, since in practice the existence of code that does something is basically an inevitability, in a world where you can only rely on impracticality for a limited amount of time and where it's basically impossible to hold a monopoly on some piece of knowledge or information forever. I think this also is rather helpful when you look at things like exploits: if someone makes a genuine mistake in their software, for which they expressly disclaimed any warranty, it would be weird for them to be culpable when it impacts an operator; but if someone were to be using said software to store user data, and that user data were leaked via an exploit in software, it's more reasonable to say the operator is responsible. Code itself doesn't usually have much intent encoded into it, so it's unreasonable to go in from a perspective that assumes that you can judge the morality of software itself.
But then, taking this to its logical extreme, it might be a little too absolutist; even if software is inevitable, that doesn't mean that culpability for intentionally destructive behavior is necessarily a bad idea.
Either way, from this viewpoint, I think you can easily argue that cryptocurrency and AI both have enormous potential to cause consequences in the world. It isn't necessarily that the technologies themselves are inherently bad, but from a practical standpoint it doesn't really matter.
https://decrypt.co/109848/ethereum-energy-carbon-footprint-d...
The most ridiculous point I've seen by far is the idea that actually, energy is not "wasted", because it's actually generating heat. It is true that computers are 100% efficient space heaters, but that's not the point.
The point is that if you scale the Bitcoin network up, it would put tremendous strain on the energy grid. That's not FUD at all!
Yep we've heard this all before.
Bitcoin vs. Meth Cooking
Bitcoin vs. Yellow Cake Snorting
etc