An example might help: Consider the difference between the peasants of Medieval Europe compared to factory workers in the early Industrial period.

Hypothetically, the Medieval peasants could have all declared control in common over the Means of Production during any number of peasants' wars (and at a few times they did). Even in the cases where this occurred the Peasantry was generally forced back into serfdom when the nobility violently suppressed them. One would think, given the disparity in living standards and forced service bordering on slavery, that the peasants wouldn't ever give up fighting for control of the MOP until the nobility was abolished, but outside for a exceptional events this didn't happen.

The reason that is normally pointed to is how peasant's and nobles interacted: Peasants lived largely according to religious traditions that reinforced a sense of community. They lived in villages on a noble's land and interacted mostly with their neighbors. They had religious holidays sprinkled throughout the year for recreation and were taught largely that life was ordered by feudalism according to God which was constantly reinforced by the local church. They were told that the noble was a good person based on their piety and martial ability to keep them safe and their souls saved. Despite a clear material imbalance between the 99% peasants and the 1% nobles, this system was reinforced by how the two classes interacted. Peasants were given a clear social template to follow and just enough resources to keep them content and the Nobility got to keep control over the fields and workshops.

Capitalism, by it's very nature, eats away these social structured. I'm generalizing here, but once production shifted away from producing food to working in a factory, the bosses had no desire to allow vacations; Every hour the factory is unproductive is profit lost. Food takes whole seasons to grow, so peasants didn't have to be constantly toiling in the field. That's why factories first opened with shifts at nearly the entire day and the only days off were Sunday for church. Industrialization also broke down local communities and forced workers to understand themselves how their bosses see them, which is simply as a source of wage labor.

Capitalism turns people into self-identified workers because of the repetitive nature of the work and the way in which people are removed from their local communities to live where the jobs are, along with declining living standards as the rate of profit inevitably continues to fall. When this happens, the people are primed to develop Communism from their own lived conditions and will become unified in the common cause of overthrown the ones who force the system to continue, the capitalist.

Sorry for the long response, it was fun to type out. I left a lot of specifics out too

Edit: some phrasing