I do not understand why this has occurred only in some countries and what special conditions do these have to be so. The class struggle itself will lead to revolution by the proletariat and the establishment of communism. Why there have not been revolutions in all countries with the development of capitalism? (Sorry for my English, I'm from Spain)
There are as many answers to this questions as there are capitalist economies. You may be interested in this answer of mine, in which I discuss the way Peruvian authors understood the failings of Marx's historiography and tried to write their own, Latin American version of Marxist history: one that incorporated indigenous people and the particular history of capitalism and revolution in the region.
Is there any one country you are interested in?
In addition to u/CommodoreCoCo's answer, you may be interested in this past comment of mine about how economic histography post WWII has moved away from the concept of capitalism as a distinctive economic system, separate to other systems like feudalism.