Yeah the FBI is just a puppet for the politicians. It's sad really.
They should be though, shouldn't they?
Politicians are elected and the FBI (and CIA and whatever other agency) is not.
So in theory, the FBI should be accountable to the politicians and the politicians should be accountable to the people.
The real issue is when politicians are derelict in their duties people often don't hold them accountable and vote them out.
And when politicians aren't held accountable they can run roughshod on agencies and whatever else.
To me it starts with the people (voters). They have to start paying attention and giving a shit about more than just party lines and things that aren't really the purview of government. And get way better at voting politicians out of office.
Instead people are content with the status quo, and especially if you personally are doing well, the tendency is to pay no attention to what's going on behind the curtain.