I think that would need to go hand in hand with social change to allow people greater quality of life outside of consumerism (e.g. greater economic stability, autonomy, home ownership, access to education, etc.).

Right now it seems that the social contract is "give up your autonomy and stability to capitalism and in return you get to consume lots of stuff". If we remove the "consume lots of stuff" part of the equation, then I doubt people would be happy with the "give up your autonomy and stability" part.

Energy efficiency is skyrocketing though. My house uses 25% the energy it would with if we installed 20 year old appliances (even ignoring improvements to insulation).

Yes you're absolutely right