Of course they charge for their service, but 'economic rent' is a term used in economics to denote value generated by other economic participants and extracted

Of course they charge for their service, but 'economic rent' is a term used in economics to denote value generated by other economic participants and extracted by a non-producing party. Miners are producing most of the value they are capturing. The portion of their earnings that is 'economic rent' is not nearly as large as that of the beneficiaries of the traditional monetary and financial system.