> LED lightbulbs, LCD TVs instead of monitors, vastly improved efficiency standards/technologies for various appliances, fact you can do loads of stuff with a smartphone instead of watching a giant TV, etc etc

It's not this. We are getting bigger tvs. Bigger monitors. Residential sector energy use is increasing.

Commercial/Industrial sector uses most of the electricity.

The decline is a reflection of the stagnation of commercial businesses/industry in the TVA area.