Acting officials typically don’t have the stature to implement new programs or regulations that would have significant effect, and lack the access to the networks that would get them help from the White House and other agencies, (Stanford law professor Anne Joseph) O’Connell wrote. …From the Time screed. There is still no way Sessions was going to be replaced with an “acting” AG under the 1998 Federal Vacancies Reform Act.
The point is that acting officials can serve for extended periods of time.
And the FVRA was successfully circumvented by President Trump for several appointments.