- Let individuals freely transact. Which as you rightly point out, has failed for good reasons.
- Prevent state institutions from controlling monetary policy. This has not failed yet - mainly because crypto is not even remotely big enough that the state has tried to control how much cryptocurrency is printed. If cryptocurrency ever gets big enough, we will find out whether it can withstand the pressure. While cryptography to secure your communications has withstood state pressure for 30 years now to not allow backdoors, I think the pressure on cryptocurrency will be higher.
How has it failed on this metric? A user holding crypto can transact freely and without intermediaries, that much is true of the blockchain. That some governments around the world may decide to restrict this activity with the threat of force (some countries more than others) does not mean it isn’t achieving its goals of a permissionless digital network.
The problem is that for the vast majority of people, the only way for X to acquire the cryptocurrency is to sign up for an exchange. And for Y to actually use it, they will have to convert to fiat via an exchange. And when signing up, X and Y will have to reveal complete financial details about themselves - home address, bank account details, identification document scans, etc.
This means that governments across the world now exercise significant control over who you transact with. And how much tax you pay for your crypto activities. If governments don't like you, they will force the exchange to kick you out. Or they will block all your bank accounts - like my own country often does - almost completely destroying your life.
This is a far cry from the early dreams of cryptocurrency, where people thought that governments would have close to zero control over their transactions. Yes, right now, crypto is a bit more free than other types of transfers, particularly for international transactions, but the noose tightens every year.
It doesn't matter what the technical details of the protocol are, what matters is what you can do in practice.
To make an analogy, see the laws and prohibitions around encryption. Many countries (USA, France, etc) have had severe restrictions on cryptography over the years; some countries like China still do have these in place, and others like UK are considering new laws that further impede access to encryption. Yet none of these policies are strong evidence of some failure of encryption technology and the ideas it has brought forth.
France, 1999:
> France to end severe encryption restrictions [...] Until 1996 anyone wishing to encrypt any document had to first receive an official sanction or risk fines from F6000 to F500,000 ($1000 to $89,300) and a 2-6 month jail term. Right now, apart from a handful of exemptions, any unauthorised use of encryption software is illegal. Encryption software can be used by anyone, but only if it's very easy to break.
https://www.theregister.com/1999/01/15/france_to_end_severe_...
You have to provide an account of your financial activities at the end of the year to your government, and lying on it will get you in serious hot water. You don't have to annually tell the government who you communicated with and how. So, you using encryption technology will never land you in trouble, unless the government catches you. For instance, millions pirate copyright material around the world, but governments find it very difficult to catch the ones setting up the sharing sites.
But any non-trivial usage of cryptocurrency has to be reported by you to the government, and if you don't the tax authorities will come after you. So the government at this point has close to complete control over which cryptocurrency transactions you can freely engage in, and which ones you can't.
How has this failed? Every month I transact in crypto while I could not do the same using traditional methods.