> Cryptocurrencies are provably inferior when you don't require censorship resistance

A) This isn't true. They also have predictable monetary policy and anonymity (or pseudonymity, in the case of Bitcoin). These can be useful properties, whether or not you agree with their uses.

B) Even if it were true, so what? Censorship-resistant money seems like a pretty cool technology to me.

> Any volatile cryptocurrency transaction requires two currency conversion steps.

Sure, in the absence of merchants accepting the currency that is true. But that's sort of like decrying the internet as useless when it came out because nothing was on it. And listen, if you want to go ahead and make a case that cryptocurrencies are structurally incapable of becoming commonly accepted - by all means, go for it. That is how you attack the concept. You don't attack a new technology by saying it isn't adopted yet:

"Cars can never work because there are no paved roads"

"Credit cards are stupid because nobody accepts them"

If you want to try to make some intrinsic, fundamental case that there is some structural barrier preventing the adoption of cryptocurrencies, that's a perfectly reasonable line of argument to make. Simply stating the obvious, that they are not yet widely accepted, is not.

> Any lottery-based reward creates mining pools, which means a few entities can and do control things.

While true in a certain sense, an analogy here might be useful: Capitalism is centralized, because people organize into corporations, which end up aggregating capital. This is an accurate description of capitalism. However, capitalism is still distinct from what's commonly known as 'top-down economic planning', e.g. communism. The fundamental difference is that the process is organic, and for the most part, empirically, the organic version of this process leads to better outcomes.

Again, perfectly fine to argue that this particular one doesn't lead to good outcomes for such and such reasons. However, to argue that it is centralized, is kind of missing the point. Yes, powerful entities do form, but their power is not guaranteed. Their power is highly contingent upon their continued performance of their duties, and the collective desire to let them keep their place. This powerfully aligns their incentives with the well-being of the ecosystem.

Now, does this mean that that alignment is perfect? Definitely not. Just like in a capitalist economy, those incentives can and do deviate from each other. However, these things do not exist in a vacuum. All tradeoffs must be considered as alternatives to competing mechanisms. And I think the tradeoff made here by crypto-currencies is a good one, relative to alternative options.

> Limit capacity fee death spirals

This whole slide just ignores the existence of payment channels. The author is sufficiently educated to know he's being disingenuous here, so there's no need to respond to it beyond that.

In summary, and I want to be totally clear on this: There are great reasons to be skeptical of crypto-currencies. There are lots of things they don't do well, and there are lots of very serious tradeoffs that they make that are different than the ones we make with government-backed fiat currencies. They pose real risks to certain pillars of civilization and it's not clear that they are on balance good things. But our criticisms of them should be couched in an understanding of those risks and tradeoffs. They offer real benefits in some dimensions, and they have real costs in others.

If someone is telling you that a politically neutral, censorship-resistant world currency is, a priori, useless, you may want to re-evaluate the source. We may or may not like what something like Bitcoin will do to the world - but the idea that it doesn't have the potential to do anything is really quite silly.