Also the courts that enforce the contracts visa makes, the FBI that chases people who commit fraud, the police and jails who enforce the decisions of the court, etc etc.
Blockchains can operate without all of those.
Blockchains can operate without all of those.
Bitcoin doesn't even try to replace contracts. Hard-line Ethereum Classic fans think they can replace contracts (they won't).
You can't use a blockchain to protect your land rights, but you can use it to protect digital rights and that means you don't need external resources like courts to spend their time on digital rights. They can focus entirely on land conflicts and other physical matters, which will make them cheaper overall.
Even if a few people in Venezuela manage to use Bitcoin (propped up by the US dollar, nobody's selling their Bitcoin for Venezuelan currency), that still easily meets my definition of a failed society.
Since I personally don't worry about centralisation and "trust", I like the idea that a system like the blockchain could be used to revolutionise payments without the need for tin foil hats and proof-of-work.