“In the social production of their existence, men inevitably enter into definite relations, which are independent of their will, namely relations of production appropriate to a given stage in the development of their material forces of production.
"The totality of these relations of production constitutes the economic structure of society, the real foundation, on which arises a legal and political superstructure and to which correspond definite forms of social consciousness.
"The mode of production of material life conditions the general process of social, political and intellectual life. It is not the consciousness of men that determines their existence, but their social existence that determines their consciousness.
"At a certain stage of development, the material productive forces of society come into conflict with the existing relations of production or – this merely expresses the same thing in legal terms – with the property relations within the framework of which they have operated hitherto.
"From forms of development of the productive forces these relations turn into their fetters. Then begins an era of social revolution. The changes in the economic foundation lead sooner or later to the transformation of the whole immense superstructure.”
https://www.marxists.org/archive/marx/works/1859/critique-pol-economy/preface.htm
The issue is to what extent the current capitalist relations of production are acting as “fetters” on the development of capitalism’s productive forces. That the most developed capitalist countries have only fitfully recovered from the financial crisis, which has worsened relations between the classes, is indisputable.
But whether the system is fettered to such an extent that we’re on the cusp of “an era of social revolution” is another matter. It’s equally possible - with the calamitous decline of the trade unions and socialist parties and the rise of right-wing forces - that we’ve entered an era of reaction and barbarism. Given current political demography, I suspect and hope we’re witnessing the wrenching dying of an old order while a new one is struggling to be born, but that seems far less apparent than it did to Marx more than a century and a half ago.