theory

The quantitative changes that eventually result in the qualitative shifts of a class society are done mostly by everyday working people who aren't aware of how their individual actions coalesce into collective action and what they amount to. For example, when I'm at work I'm just trying to get through my 10 hours and get home to my family and to play minecraft, I'm not consciously aware that my work is quantitatively adding on to the development of the productive forces.

People probably weren't inventing clay storage vessels with the hopes to eventually change the relations of productions of their communalist society. They were probably just like, "dope, these berries are gonna stay good for an extra couple days."

In the transition from nomadic pastoralism to sedentary agricultural production, in places like Mesopotamia, if I were a farmer, walls, cities, and irrigation are technological innovations that would probably look appealing to me to be a part of. The division of labor (including the bureaucratic control of surplus goods) is also an innovation but of the relations of production instead.

Keep in mind, you're probably not walking out of the woods to see these cities. Most people are born into these new early fuedal/slave societies. It's all you've ever known and it's reinforced through not just incredible violence but culture and especially religion. Your city has a patron god and your ruler was chosen by your god. Who are you to ask what they do with your grain?

I highly highly highly recommend Chainslayer's videos on YouTube that cover the history of human societies from the emergence of class, the state, and money all the way to the industrial revolution. They're a marxist using historical materialism. They're easy to understand and pretty comprehensive.

Here's the link to the video of theirs that might directly answer your question.

https://youtu.be/YMb_ojeZ_gI