If it's this clear, I'm sure you can give a quote? Marx was clear that capitalism produces booms and busts, which implies non-monotonic development. He did pre

If it's this clear, I'm sure you can give a quote? Marx was clear that capitalism produces booms and busts, which implies non-monotonic development. He did predict that, when left on its own devices, capitalism will in the long term collapse on itself due to the tendency of the rate of profit to fall. Collapses where huge governmental intervention in economy is needed happen quite consistently. E.g. in the USA the market mechanism collapsed in 1893, 1929 and 2008. And it is arguably still on central banks' life support. What Marx and revolutionary marxism was maybe a bit too sceptical of was sustainability of social democratic states, known also as mixed economies. Altough it does seem that most mixed economies (e.g. the nordic countries) are regressing towards more capitalist domination. Capitalism and socialism aren't some specific systems and no country is 100% either. Even USSR didn't say in its dogma that it has achieved full socialism, let alone communism.