Realistic spy fiction is hard. On screen, it's almost never done. The tendency to romanticize espionage is so ingrained in us through decades of James Bond and Bourne and 24 that a warts-and-all depiction of the way intelligence agencies actually operate might not even make sense to much of the moviegoing public. Occasionally, someone will make a minor, based-on-a-true-story attempt – The Good Shepherd with the CIA, for example, or Breach with the FBI – but those are viewed as history lessons, not spy thrillers.
That makes sense. The CIA doesn't exactly have an open-door policy, so it's hard to say for sure, but by all accounts the work of a real-life agent isn't terribly dramatic, or ripe for genre film treatment. Much of it is a bureaucratic nightmare, and the jobs that we view as exotic and exciting – "secret agent," for example – are usually a tedious slog, consisting of years of building connections and forging allies in the hopes of a payoff in the indefinite future. Yeah: all else equal, I'd rather watch Jason Bourne kick some bad guys in the face while searching for his true identity.