Because continual growth is counter to nature’s law and thus unsustainable, as nature assigns a value to strength, not length, and markets are manmade manacles that in actuality do not exist and confound consequence with cause, responsible for the grave depravity of reason (Nietzsche). So, the study of economics today is a pseudo-science that aims to regurgitate hindsight to project foresight to break the norm. An implausible predicament proved wrong all too many times.
Growth for the sake of growth is the ideology of a cancer cell. — Edward Abbey
Economics must be reinvented. Not with another religion of voodoo and fuzzy complexity, but with a system designed to be compatible with nature’s law, using (our best understanding of) the only principles that determine the health, quality, ingenuity, capacity, and length of our species on earth.
We must redesign the operating-systems for humanity with a 4.5 billion-year-old thoroughly proven thesis that determines what we can discover (Einstein), using the principles of nature as laid out in green in the enclosed chart.