To answer the question: "Why already now, 80 years after the October revolution, capital dominates above the world?" - a successive follower of the historical materialism will try, first of all, to clear: was the level of the development of productive forces of mankind (first of all in the most-highly-developed countries) in the 19th - first half of 20th centuries sufficient to make proletarians capable to organise the ruling over production, distribution & exchange by all the society as a whole (and so, to cease to be proletarians)?
Karl Marx wrote about the grounds of the coming proletarian revolution:
"Hand in hand with this centralisation, or this expropriation of many capitalists by few, develop, on an ever-extending scale, the co-operative form of the labour-process, the conscious technical application of science, the methodical cultivation of the soil, the transformation of the instruments of labour into instruments of labour only usable in common, the economising of all means of production by their use as the means of production of combined, socialised labour, the entanglement of all peoples in the net of the world-market, and with this, the international character of the capitalistic regime. Along with the constantly diminishing number of the magnates of capital, who usurp and monopolise all advantages of this process of transformation, grows the mass of misery, oppression, slavery, degradation, exploitation; but with this too grows the revolt of the working-class, a class always increasing in numbers, and disciplined, united, organised by the very mechanism of the process of capitalist production itself. The monopoly of capital becomes a fetter upon the mode of production, which has sprung up and flourished along with, and under it. Centralisation of the means of production and socialisation of labour at last reach a point where they become incompatible with their capitalist integument. Thus integument is burst asunder. The knell of capitalist private property sounds. The expropriators are expropriated."