Redefining a high standard of living doesn't mean having a low standard of living, but it often means living differently than we have in recent decades.
For example, you can live a luxurious lifestyle in an energy efficient way by living in a smaller and efficient house. If it's an all electric house your standard of living can even increase due to better indoor air quality.
Multifamily and village style walkable neighborhoods, whether in rural or urban areas, and where people make fewer long drives for work and groceries, can also improve quality of life.
But unfortunately those kinds of lifestyles are not very attainable, and rarely affordable in places in the US.