Is the role of inflation over inflated?

Credit here to Ben Phipps and Sam Udeshi at Chauncy School, Ware, for highlighting this great graphic and short article about how the actual prices of a range of goods and services compare with what their price should be when adjusted in line with the RPI since 1981. It shows how some products are cheaper than inflation trends suggest they should be, whereas leisure based items are noticeably higher. Can students explain possible reasons for this?