Like all federal agencies and departments, if you were to cut the FBI in half they would still be able to accomplish their actual needed tasks. Government et al. has grown to large.
Every politician wants to create more government, and Republicans are just as guilty! They simply create crap like the TSA, Department of Homeland Security, and fund a pointless and endless war on drugs and other idiotic nonsense. While libs and Democrats want to grow government in the name of social justice, welfare, for the children, environment and their causes, the so called conservatives want to grow government in the name of public safety, national security, and their causes.
BOTH are equally guilty of the massive government and tax burden Americans face today. Roughly 43% of GDP is in some shape or form government at either city, county, state or federal level.
Exactly why we need more President Trump and a hell of a lot less Career Politicians.