No, there isn't a single root of all evil.

everyone hates capitalism, and it pisses them off, but they don't know they hate capitalism, so they just complain about every issue individually as if it's some series of unconnected phenomena with no root cause

I disagree with this whole sentiment so much, it's like everything I dislike about other leftists summed up in one bad paragraph.

I've studied politics for years, and I can say this with absolute certainty: No, all of the problems with society do not have a single root cause. In fact, it's the polar opposite: Every single problem with society has multiple unrelated causes, all of which need to be identified and addressed and fixed separately. And fixing them often requires multiple solutions, many of which aren't intuitive or immediately obvious and can only be determined through careful analysis, study, and trial-and-error implementation.

The notion that there's a single "root of all evil" responsible for all the world's ills is one of the most self-serving, overly simplistic, intellectually lazy ideas possible. And the belief that we can fix everything wrong with society by simply getting rid of that one Big Bad Thing is the worst sort of arrogant idealism. It's the exact same logic that fuels conspiracy theories and, in many cases, outright bigotry. It's Single Cause Fallacy exacerbated by ideological devotion and political tribalism, with a hearty helping of Outgroup Homogeneity Bias on the side.

P.S. If you feel like responding with something along the lines of "that's just what the evil capitalist elites want you to think, you can't trust what you've learned in school because they control all the universities," please refrain. Also, please reflect on just how circular that line of thinking is.

P.P.S. If you're a capitalist libertarian who likes this post, but also blames the federal government or the existence of states in general for all of the world's ills: congrats, you're doing the exact same thing I'm criticizing here. The underlying logic is bad, whether it's capitalism or government or White people or the Jews or the Illuminati or lizard people in human suits or interdimensional DMT aliens you're scapegoating.