The immoderate political left began speaking and writing of late[-stage] capitalism with the end of the First World War.

The idea has been that the industrialized world has entered the final stage of something called capitalism, with a revolutionary change to some form of socialism just around the corner…

…for more than a century now.

(Actually what we've seen is a slow, grinding transformation away from the use of genuine markets to an administrated order, which in more recent years has threatened to become a neo-feudalism. The transformation began well before the First World War, as technocratic thinking began displacing liberalism.)