Blockchains rely on intermediaries to process transactions. The difference is, in a blockchain-based system, the end user has no freedom at all to choose which

Blockchains rely on intermediaries to process transactions. The difference is, in a blockchain-based system, the end user has no freedom at all to choose which intermediary they want to use. The intermediary is chosen at random, according to how much useless computations they have done. And because of these useless computations, the system is also less economically efficient, in other words more expensive, compared to alternatives.