First, thanks for that forthright assessment of a fraught — in more ways than one — idea.
As alluded to in the article, degrowth has mostly focused on the microeconomic realm for the simple reason that changing the economic system is seen as being such a big of a political hurdle that it might as well be completely ignored. It is hoped that all relevant participants will adopt this or that approach to production as well as consumption throughout the economy for the sake of degrowth — and thereby the natural environment —for the benefit of all of humanity, but adoption of 'best practices' would be at the level of individual entities.
[For the record, I do have an M.A. in economics.] I have (fully) developed a paradigm that would achieve degrowth at the macroeconomic level — without changing the structure of the existing economic system (in any nation), including as part of the system the rules governing participation in it (to include the existence/extent of private property and the profit motive). Output would be governed, passively but effectively, by demographics. The extant political imperative to maximize output/total income in order to maximize employment and the collection of taxes (at whatever rates exist) would be ended: neither employment nor the funding of government would be dependent in any way on output/income.
You never can tell where a good idea might come from — in this case basically a hick from Georgia (U.S.A.) punching above his weight intellectually because he happened to stumble upon a great idea: create money as needed to fund a (‘livable’) guaranteed minimum income — one for which any adult citizen could become eligible — and all government, from local to national, forevermore at the current per capita rate of total government spending. The hardest part was figuring out a mechanism for withdrawing money from the economy (in the absence of taxes, as in MMT) such that individuals and businesses could retain plentiful pools of money and bountiful baskets of assets (based on income) and no money would be collected from any person or business before it could be used for purchases/investment.
The result is no unemployment or poverty (for any adult citizen) at any level of total output and no taxes or public debt (if not permanently, at least reset at zero) in a self-regulating economy with systemically increased sustainability. All of that is accomplished without having to redistribute anything, without imposing any cost on any employer, without imposing any limit on income/wealth, and without requiring people to act any particular way, whether altruistically or any other.
If curious, "A Most beneficial Economic Change" is a "2 min read" here in Medium with links to articles about the paradigm from various angles.