The overall problem is that everybody's meter will need replacing at some time due to (alleged) obsolescence. When that time comes you cannot refuse to allow your meter to be replaced and the replacement will be a so-called smart meter.
In the meantime you can decline their generous offer of a meter which will do nothing for you, will possibly present problems if you want to change supplier and will, eventually, allow the supplier to have control over your supply. It is true that some suppliers are only providing their best tariffs on the condition that the customer has a smart meter. I did read some time back that there was a court case pending challenging that stipulation but I cannot find any trace of it now.