Gasoline is 100 times more energy dense than a battery. The Tesla roadster adds 800 lbs to the lotus elise upon which it is built. Batteries have a long way to go.
Left to their own devices, people would never upgrade. This is a security risk for MS. (Win 8 support ends January 2018). Chrome was championed for auto updating, and now all browsers do the same. Web apps can auto update whenever they want. Mobile apps auto update. Why shouldn't operating systems?