A hundred years ago the discussion was straightforward: capitalism or socialism.
But now you notice a slightly different kind of discourse re: “post-capitalism” … “alternatives to capitalism.”
“We still have no doubt that capitalism is an unsatisfactory socio-economic system; but whether or not ‘system change’ means ‘transition to socialism’ is not so certain anymore.”
People are still left wondering, conjecturing re: “what would a post-capitalist society look like?” … because after two hundred years of the existence of the world-historic socialist movement there is not yet a single enduringly successful implementation of the idea.
If there was, people could at least try to compare systems. Around 1930 there was the idea that one could do an evaluation of that kind by examining the society of the USSR … or would soon be able to. There were many people circa 1925 to 1950 who said “don’t compare yet, the USSR is just in the process of building socialism.” The country had been set back by defeat in WWI and then the civil war of 1918–1920 and then the Nazi invasion of 1942–1945. But with stabilization after 1950 some said the evaluation could be done. Some (very few) said socialism had been achieved in the USSR and life for the masses was better, superior. That viewpoint completely faded between 1950 and 1990.
So now some socialists are talking about: Proto-period (1820–1848); First Era (1848–1917); Second Era (1917–1990); Third Era (current).
But some are conjecturing about other post-capitalist alternatives.