Very good thinking, but there are many hurdles challenging this idea. First off, people have to accept the idea of "enough." That is hard without a prior collapse or trauma caused by excess. But even if the first generation accepts these norms, things tend to degrade over time. You may want to research Israeli community of "KIBBUTZ." The innitial enthusiasm always wears off.

The reall challenge with the transition we are facing is not in WHAT (we have the solutions already) but with HOW. How to make people understand that they have to let go of our comforts that are killing us all? I see no way without a collapse first.