There is a change that can be made to the existing economic system to combine sustainability with other societal concerns, such as unemployment and poverty. Any nation could adopt this change--with a single Legislative Act.

Currently in every nation there is a political imperative to maximize total output in order to maximize employment, total income, and the collection of taxes. With this change total output would be governed, passively but effectively, by demographics. There would be no unemployment or poverty at any level of total output. There are built-in protections against inflation.

A brief overview is in "Permanent 'Quantitative Easing'" (here in Medium, but not behind the paywall). Personally, I am convinced that "To Preserve What We Have, What We Have Must Be Enough" (also in Medium but not behind the paywall).