>Line employees often do not have a big picture understanding of the work they are doing.

Been a while since I read Graeber's book but I recall one self reported "bullshit job" being to lift rocks scattered across a field and put them in a pile. The people doing the task thought it was a time wasting activity as they were unaware that winter frost pushes up new rocks every year.

It's possible that a lot of these so called bullshit jobs are just jobs where the purpose hasn't been explained to the employee.