For a start, I suspect that the energy usage by the meter's electronics is totally trivial, probably nothing like "£20 per year".Unlikely. It operates at your cost by way of standing charge. If they increase the phone home frequency, your standing charge goes higher.
In any event, the entire cost of the provision and deployment of 'smart' meters (which is far from trivial) is ultimately borne by consumers, whether as part of the Standing Charge and/or the Usage charges.
Kind Regards, John