Like all historical thinkers making claims in economics, sociology and history Marx was wrong about a lot of things. So was Smith, Ricardo and countless others. However that doesn't settle the question if there is an updated version of some descriptive or normative claims traceable back to Marx, Smith or Ricardo that is well supported today. Agree?

"wealth would concentrate more over time", which it in fact did and keeps doing, on some measures such as the absolute GINI.