I agree, they are, but Graeber's the type of dude to prioritize making a playful argument over making a rigorous one. Debt has a whole chapter arguing that Muslim banking is better than European Banking because it obeys Abrahamic usury laws. He then included a footnote basically saying "I know it's still capitalist, I mostly wrote this chapter to troll evangelicals."
Like, he has brilliant insights, but not necessarily brilliant analysis. Take him as a supplement to your theory, not your main meal.
Throw in the Situationist International and Midnight Notes and this is just my politics