That's because they are kept milquetoast as a way to nullify any left-wing movement.
https://theintercept.com/2023/03/21/fbi-colorado-springs-sur...
https://jacobin.com/2018/08/fbi-infiltration-new-left-aoki-s...
https://www.npr.org/2021/07/01/1012107432/how-a-former-spy-t...
https://indypendent.org/2019/02/lessons-from-the-fbis-secret...
https://theintercept.com/2023/02/10/deconstructed-fbi-inform...