I should add that the "legitimacy" narrative still very much exists to the present day in the Western discourse throughout the propaganda in the media and in academic works on contemporary socialist states. It's like shining a UV light on a shoddy roadside hotel room in that once you recognize the narrative utility, you start to see it everywhere like an ooze. It's particularly evident in coverage of China and Vietnam, through less so with the DPRK and Cuba because the economic warfare against the latter two states has encouraged their governments to actively emphasize the inherent value of socialism against the (historically nihilistic) logic of the "legitimacy" narrative. This Western propagated narrative festered across socialist states in the late 20th century and drove those states to the decisions of pursuing IMF loans and neoliberal Chicago school shock therapy which brought about capitalist restoration and the progress of Cuba and the DPRK in maintaining socialism in spite of their externally-induced economic hardships is a positive step to countering the narrative.

To summarize, "legitimacy" is one of those irregular verbs in the Western dictionary: "You seek continual legitimacy but I have a perpetual, unquestionable right to rule." The concept never applies to the Western capitalist structure even with the routine collective generational economic trauma inflicted from the boom-bust "business cycles." Japan has now gone through three "lost decades" of stagnating GDP per capita and yet its socioeconomic condition will never be discussed in the narrative framework of "legitimacy" for obvious reasons, whereas every single fiscal quarter of perceived lackluster economic performance in China and Vietnam brings about endless citations of this narrative like clockwork.