Another argument against the "going dark" claim is that before smartphones and the internet, the only conversations the FBI could monitor was through phonelines and mail. These were known to be easily monitored and I doubt there was much more criminal activity happening through those then than now. I would argue that the conversations that have gone online are the interactions that were previously happening in-person…
It's arguably different industrial complexes that have lead to mass surveillance, perhaps mostly the military-security industrial complex, that has lead to the current path; fear as a distraction from what's really needed is healing and strengthening the individual to not be brittle and prone to manipulation.