Members of Parliament have a duty to listen and respond to their constituents, which in Sunak's case is the people of Richmond, North Yorkshire. I don't live there, but I have lived in a senior government minister's constituency in the past. I wrote one letter, and I did get a reply — I doubt my letter was directly read by the minister, but it was probably tallied up by an assistant "15 letters supporting this so far, 8 against".