I have worked in the government for over 20 years. Whenever there is a change in the administration, the appointees of the departments/agencies are ousted. There should be a “litmus” test and if the department/agency is doing well, the agency head that answers to congress should stay.
It’s disconcerting for employees to have to change policies that work just because it’s a new administration. It can also be a burden because you have to “start from scratch”, wasting taxpayer money.
An example: I work with USDA and when I started, the agency head was Secretary Sonny Perdue. He removed policies from the prior admin that were not well received and manpower was spent rewriting policies. Then Secretary Vilsack replaced him when a new administration took office. Once again, policies and procedures were changed, wasting time and money.