Another reason in favor of reliance on contractors, at least in a couple of federal agencies I’ve worked with, is to improve diversity metrics. For agencies that require lots of technical workers, the reality is that means a heavily male workforce. But agencies (up until a few months ago) liked to tout that they were “model employers” with very diverse workplaces, and near gender equity. Then you actually show up and notice the building is full of the usual (for tech) contingent of white and Asian dudes but they don’t count as employees for diversity statistics.