The problem i have with Marx's theories is very meta.
He breaks down the world into two classes, and heaps all the blame on one of them.
However, he misses a third class, and in doing so, fails to identify actual solutions that work.
The entrepreneur. The inventor.
Sure, when you have a working factory, its easy to point out that the workers are getting next to nothing (99% of the revenue, split 990 ways) and the owners are getting everything (1% of the revenue)
But the reality is the factory doesn't exist without the third class creating it out of nothing.
And socialism / communism does its best to destroy this third class. One by making it economically unviable, the other by just killing them.
Then there is the class theory that divides the world between the political class and the economic class. The former operates by real plunder, not the "exploitation of the worker" charged by the communists with their fixed pie fallacy. The latter engages in voluntary exchanges that build wealth.