This reasoning fails to take into account the oppressors' possession of technology. Slower forms of communication may have sufficed in the situations you've cit

This reasoning fails to take into account the oppressors' possession of technology. Slower forms of communication may have sufficed in the situations you've cited (wherein the oppressor had faster-but-still-slow means of communicating), but when the oppressor has access to instantaneous communication and you do not you are at a severe disadvantage. This is precisely why public access to instantaneous communication is being revoked at this time.