What happens if consumers become "frugal"?

We can imagine a scenario in which consumers in OECD countries become "frugal": they reduce their consumption because the COVID crisis has shown them that it is not essential to consume that much, and because concern for the climate and the environment encourages them to spend less. So a return to the pre-COVID crisis level of consumption would be impossible even if household demand was stimulated . What would happen then? If this shift towards "frugal" consumers occurs in a single country, this country will experience a "German-style" development: high household savings rate, excess savings overall, economic equilibrium with a considerable external surplus that replaces household demand; If it is a global development, then there will be a fall in production and in the required potential production (fall in consumption, fall in investment requirements), leading either to mass unemployment, or to a return to full employment through a fall in real wages.