Honestly, I don't believe that capitalism was ever a progressive force; the work of Sylvia Federicci is good here. Though it depends on what we mean by "progressive." If we mean progresses things towards communism, sure. But if by "progressive" we mean anything like "made the world better, or individual's lives better, in any way whatsoever," then no, it never was progressive and past Marxists were wrong about that IMO. Capitalism creates the conditions for the possibility of world communism, and in that sense was a positive development. But it made the lives of basically everyone worse, it was better to be a worker under pre-capitalism formations by and large. It's destroying the planet. The tech it produces may be "redemed" under communism, and so is good in that sense, but is currently nightmarish. Also, I think seeing capitalism as only a mode of production leads to distortions and errors in analysis, one needs to view it as a world system. Here, one can understand that although certain past AES countries were able to move beyond capitalist relations of production, they were still embedded in the capitalist-imperialist world system (even if as a resistant actor). This helps to explain the behavior of modern China, IMO.

Also, I'm very drunk currently, hope this makes sense.