The basic notions of class society and materialism I agree would have developed regardless. We are, however, very lucky to have had, in particular, an expert whose PhD thesis was on the question of free will in the context of materialism; that this expert also deeply understood the dialectic and popularized that as the theoretical foundation of the nascent capitalist world; and that this expert politically favored working-class socialism over bourgeois socialism (communism over socialism). Marx had a longitudinal view of the history of socialist thought and of economic thought. The sheer clarity of the ideas may have saved us from centuries of confusion and quasi-religious fighting over the precise formulation of these principles. Someone like Lenin might not have succeeded at combating liberal dogma without this clarification being handed down at the right moment in history.
The basic notions of class society and materialism I agree would have developed regardless. We are, however, very lucky to have had, in particular, an expert whose PhD thesis was on the question of free will in the context of materialism; that this expert also deeply understood the dialectic and popularized that as the theoretical foundation of the nascent capitalist world; and that this expert politically favored working-class socialism over bourgeois socialism (communism over socialism). Marx had a longitudinal view of the history of socialist thought and of economic thought. The sheer clarity of the ideas may have saved us from centuries of confusion and quasi-religious fighting over the precise formulation of these principles. Someone like Lenin might not have succeeded at combating liberal dogma without this clarification being handed down at the right moment in history.