Graeber's claim about bullshit jobs can be trivially dismissed. If there were actually many bullshit jobs in some profitable company then eventually a competitor with fewer bullshit jobs and thus lower costs would come in and eat their lunch. While middle managers in some organizations do engage in empire building to inflate their own importance, senior executives generally don't hesitate to cut costs by laying off unproductive employees. Their own bonuses and equity values depend on this.

There are certainly some bullshit jobs, especially in the public sector and non-profit space. But they are a tiny minority.