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.