3 out of 4 great books. Nice reading list.
The person of Karl Marx, and his all-encompassing ideology, can be best summed up in this painting from Montenegro (I don’t consider it an icon):

With that being said, there are things that I think Marx is absolutely right about - for example, how money is able to morph one’s perception of reality (such that ugly people are now lusty, fat people are muscular, stupid people are intelligent), or about the inherent self-destructive nature of Capitalism insofar as technological innovation is concerned - I.e., as technology allows production to be more efficient, division of labor becomes more extreme, which will ultimately lower the demand for skilled labor and raise the supply for unskilled labor, lowering the cost of unskilled labor, such that the masses get less and less for unskilled labor, to the point that living conditions become dire and horrendous, leading to inevitable societal collapse and unrest.
That being said, look to his earlier essays he wrote when he was younger, like “On the Jewish Question” (which isn’t really about Jews) because the Communist Manifesto doesn’t go too in depth about how Marx perceived the world or his rationale to the degree that his individual essays do; it’s just a basic definition of what Communism is, a logical argument for communism and how it can achieve its goals as a political platform.