The sole purpose of blockchain is to prevent double spending without a trusted party Other proposed applications are mostly dumb / misguided, like immutable storage, social network posts, etc, these can be done with hashing or digital signatures alone If you have a better way to avoid double spending than blockchain folks woukd get very excited. Traditional database can’t do that (requires a trusted party)
> The sole purpose of blockchain is to prevent double spending without a trusted party. Yes, and avoiding the trusted party makes it more inefficient by a factor of around 100,000,000 (-ish), if you consider that BTC uses around 23 GW and can do no more (5 transactions a second) than a single trusted PC could do. What are use cases were you actually need this and the high cost is worth it?
Some people feel strongly this security is worth it. Some feel strongly that it isn’t (but one suspects their objection is really to the lack of central control)