I completely agree with you. A significant part of the degrowth discourse is indeed about the responsibility of the global north to take the lead in a manner like you describe. Given the outsized, even hegemonic economic influence of the United States (at least for now), that example could have real impact. But like you I am pessimistic about the likelihood of that sort of agenda ever taking hold in this country, and so I'm pretty well convinced we'll get degrowth by force of circumstance rather than by choice or design. Maybe a better word for that is 'collapse', and the prospect frightens me, but I also like to co-opt a statement by the cursed Milton Friedman, who said (paraphrasing) that crises inevitably bring change, and the shape of that change is determined by the ideas that are lying around at the time, so we want to make sure our ideas are at hand when crisis inevitably strikes. I largely think of the conversation around degrowth in those terms.