You have a misunderstanding about Marxism. Marx already knew about the monopolistic nature of capitalism. This nature leads to concentration of power in the hands of a few owners of capital, while everybody else is stripped of ownership. This is not very different from the serfdom of middle ages. Marxism proposes to solve this by abolishing ownership, so no-one can control the capital, which becomes a shared resource. So the difference is not on the process (it will happen as he described) only about who controls it.