I strongly disagree with this, personally. The labor theory of value is part of the explanation of the production and extraction of surplus wealth, a process which Marx certainly understood as being 5,000 years old by the time Das Kapital was published. In traditional empires, the process is naked and hard to miss. In capitalist times, the rulers claim they don't do it any more, and the process no longer depends upon naked tradition and obviously arbitrary power. It's concealed by "the market," in other words.
Marx's obvious prediction is that class domination, which rests on separating the masses from the surpluses they make, will always lead to perversion and conflict. Capitalism is no exception. In fact, the ironies of capital accumulation make its development more, not less, predictable than prior class systems. Follow the work; follow the money.
Jettison the anthropology/sociology of all this is you wish. But then you have to provide some account that refutes it all at the level of history. Quibbling about the strong but not complete correlation between values and prices ain't that.