[grey-area]

Yes one of the big problems with cryptocurrencies is that they solve problems that nobody has, which in turn create problems nobody wants (for values of nobody < 0.0001% of population).

We don't need or want a trustless distributed consensus currency...

We don't need or want a fully public ledger...

We don't need or want to be in charge of their own keys...

We don't want to deal directly with other agents without a middleman to protect us from fraud and theft.

Slow transactions and distributed public ledgers are built into the design of something like bitcoin and are fundamentally tied to it - take away all those things by redesigning it or trying to augment it and you're left with a bad copy of a centralised transaction network. People need to trust their money and trust the agents they transact with, validation of identity (something bitcoin actively works to undermine) is key to financial transactions, it should be central to any network.

There really are some fundamental flaws in the design and in the aspirations of currencies like bitcoin which mean they will only ever be used by a tiny minority. Hence bitcoin has recently become a vehicle for pure speculation instead, which will end very badly when this bubble bursts.

[hanniabu]

> without a middleman to protect us from fraud and theft

The blockchain and smart contracts serve this purpose. Regardless, there's additional protocols and tools being created for decentralized insurance, escrow, custodians, etc.

[grey-area]

> The blockchain and smart contracts serve this purpose.

They do not, and the bitcoin blockchain in particular eschews identity verification in favour of pseudo-anonymity and puts people in charge of their own anonymous keys - perfect for criminals (anonymous enough to evade police) and states monitoring citizens (not anonymous enough to evade states, lasts forever for retrospective enforcement), but terrible for normal citizens who just want to be sure who they are transacting with and be able to get compensation if they are defrauded.

Blockchains and smart contracts are no substitute for real-world contracts enforced by courts and regulators, and the cryptocurrency attempt to supplant state currencies and their legal supports actively undermines any attempt to get regulators to seriously go after fraud. So instead regulators have classed them as assets (so they can tax every transaction in theory) and washed their hands of them.

[cortesoft]

The blockchain only solves the trust problem ON THE CHAIN itself. However, everything useful is going to involve something off chain, at which point we are back to having a trust problem.

Take, for example, the simplest use of currency... I want to buy an item that someone else is selling. The blockchain can verify that the buyer has sent the seller money, but it can’t verify that the thing the person bought isn’t defective. It can’t even verify that that person even delivers the item to me. It can’t verify that the item isn’t stolen.

Credit cards can help remedy the situation for all of those things.