That we have a mixture of pressures from regulations, unions, office politics, etc. that result in people being paid to do jobs that don't need to be done?
And I don't disagree with him. But Graeber's other shoe is basically that the idea for working for wages is not mankind's natural state and that the way we really wanna be is using each others' favor bank so that everyone gets what they need without anybody having to do anything fundamentally useless.
The problem is if we go back to the Land Of Primitives where we're all sharing childcare and hunting and gathering and weaving baskets, the guy/girl who does fuckall all day is a burden on his family, not on his tribe and in this, our modern billion-person tribe, we've developed ornate structures whereby the useless are given marginally useful tasks because a semi-competent person in the slot beats leaving it open.
Douglas Adams had working society conspire to launch their dead weight into space with a "no, no, you guys go ahead we'll catch up later" ruse. In the real world we have the problem of (1) all agreeing on who is worthless (something something eugenics) (2) all agreeing on what to do with them (something something Godwin's Law).
Graeber likes to talk about useless social structures but not so much about useless members of society. The fact that he refers to "lobbyist" as a bullshit job is more of a political statement than a factual one; a lobbyist hired by my wife's professional organization makes us an extra $1500 every time we have a Medicaid delivery and sure - in an ideal world we wouldn't have needed to rely on a lobbyist but in an ideal world we wouldn't have to rely on money either. Plowing through everything to get to the "no money" point looks a lot more like THX-1138 than it does like a Town Called Perfect.