IMO....
From my perspective, the lower rung public sector employees actually do a good job, work hard and try to do the right thing.
That said, once we get into middle and upper management levels (layered bureauacrcy) or at the senior level of those considered “subject experts”, the law of inertia takes over, things at rest tend to stay at rest unless affected by some other force. Except for the military, there is no force multiplier effect in the civilian public sector, in fact, it is the one area where more is less.