You have to wonder. In an age of advancing technology why are vehicles so heavy?
When vehicles had frames, thicker sheet metal, and there were no plastics. It was almost expected that vehicles were heavy, not very efficient, used a ton of gas.
Today we have all sorts of technology, its not body on frame, its unit body (a big shell), its not thick sheet metal, its high strength steel here and there, its a ton of plastics, its aluminum, in some cases its even carbon fiber.
Its still heavy....go figure.
Must be the safety equipment?
Must be the ever increasing technology content?
Its combination of a "ton" of factors, save weight here, ad weight there, and the end result is not much lighter.
Ford engineers an aluminum F150 which saves weight, while the end result is not that much lighter, and the competition embarks on a mission to prove that steel is better/stronger than aluminum.
You would expect vehicles to be lighter, more efficient, than they are.
Although they are safer, have more features, higher technology content, are on the cusp of driving themselves.