Reading anything without the help of AI will help you become a better writer because you’ll learn new ways of using words and sentences and syntax in a way that people write naturally. It seems weird to focus on Marxism, but if that’s what gets you reading, go for it.

Reading in general will help you in writing. Marx can be a very difficult read for beginners, but read his style will help with a much higher level of writing.

What is your proposed mechanism for the improvement?

I mean, it might help with worldbuilding.

Only if you’re writing fantasy.