Have you heard the expression "whistling past the grave yard?" Those adherents of capitalism who haven't noticed its inherent instability, as proven over the last two hundred years, seem to believe capitalism is a natural law, like gravity, for example.
It's not.
It is merely the latest in long line of economic systems dating roughly from the development of fire. Marx called this initial stage "primitive communism" which came to its end with the development of private property. This coincided with large scale agriculture which generated productive property like cattle and, of course, human slaves.
The second stage, according to Marx, was a slave society and this is where the concept of "class" and "state" arise; the former consisted of slave-owners and slaves, and the second develops as a tool for slave owners to more easily control their "property."
Feudalism come third in this progression after greed collapses the slave society. Theocracy, hereditary elites and classes, and the formation of the modern nation state all rise due to their inherent bonds with the Money Power.
Capitalism replaced the feudal serfs with wage labor in much the same way the serf replaced the slave during this fourth stage of development. Market economies and laissez faire economics generated vast, private fortunes by corrupting government to socialize cost and poverty among the majority while privatizing profit for a tiny minority.
Socialism comes fifth after the greed of the few results in producing a working class consciousness in the majority. For the first time in history productive forces are free to develop in a democratically planned way without the vast waste of capitalist anarchy.
Communism comes last,
and it never exists until socialism and capitalism have run their historical course.
https://en.wikipedia.org/wiki/Marx's_theory_of_history#The_stages_of_history
"Fiat money and credit whose values were determined by anarchic market forces are abolished.
"Instead, in his Critique of the Gotha programme, Marx speculated schematically that from the 'total social product' there would be deductions for the requirements of production and 'the common satisfaction of needs, such as schools, health services, etc' which latter deduction 'grows in proportion as the new society develops', and, of course, deductions 'for those unable to work, etc'.
"After these deductions the workers could divide up the wealth produced by their labor and everyone could be simply given a 'certificate from society', which could then be exchanged for products.
"This schematically introduces a means of exchange ('the same principle' i.e. money) in socialist society but with the speculative element removed."