There are 2 types of federal employees. Bureaucrats, in my view, are those who join government service to 'make a difference'. Could be left or right, but essentially zealots who join to make things happen on the policy side. These are 'officials' with large or small policy making ability (which may be formal or informal).
The others, I call Civil Servants. Those are people who work government jobs because that's who hires people in that career field. These are most often skilled or semi-skilled positions.
I am not advocating term limiting apolitical workers. Engineers and park rangers are not typically bureaucrats, they are civil servants. I am talking about those primarily in DC who 'advise' on policy and push paper.
As for pay, while cash may not be great, the perqs are nice. My brother is a GS15. He retired as a Major, USAF and now double dips. More importantly, those in DC and a few elsewhere who use their experience in government to enrich themselves. Graft, sweetheart deals, etc. Not all money comes from salary tables.