To say you're completely ignorant to the work the FBI does would be the understatement of the year. You seem to believe that though technology has changed the entire world, the FBI should still be operating as they did 30 years ago.
Here's a case they worked in which the use of technology to crack an iPhone was the key to saving a child and putting a very bad person in jail.
Some years ago, a 6 year old went missing in the southern United States. There was little in the way of evidence in the case and things went cold after a month or two. It likely would have gone unsolved if it wasn't for the FBI and their continued investigation on another case. They came across pictures of another child, which lead them to the suspect in question.
Most of the evidence in this case was digital. In your mind, they shouldn't even be bothering with it and would have left things as that, moved on to something else but thankfully they kept pushing. They secured a warrant and were able to gain access to the suspect's iOS device. What they found were hours of recordings. This guy didn't get off on the rape of the missing child but rather on listening to the recordings he made of those rapes.
With this evidence and more contained on that phone, along with further digital records obtained elsewhere, they were able to make an arrest, locate the child and return him to his parents 2 years after his abdication, and put this guy away for a very long time.
So when you say that they should go back to using "real crime fighting techniques" you're completely missing the fact that the entire world has gone digital and they're out there doing hard work that no other law enforcement agency is doing. They're putting away very bad people and helping to fix broken families.