Radio was definitely a great platform for propaganda among authoirtian states, but the nature of radio infrastructure lends itself to be controlled by the state so if the state is authoritarian then they will naturally turn the radio.
Facebook is a platform that has no borders, and it is ubiquitous in a way that TV, radio, and even other parts of the internet are not. Add on the all seeing nature of AI and machine learning and I think over time Facebook could definitely prevent the spread of these ideas on it's platform.
The major point of contention for me is the question of if it's Facebook's rightful place to regulate political speech, Zuckerberg definitely seems adverse to putting his thumb on the scale but at this point I'd say that not weighing in is a form of weighing in. The bring up the often cited Voltare/Ben Parker quote: "with great power comes great responsibility", Facebook has reaped all the benefits of becoming the social infrastructure of the internet, at some point they have to draw a line in the sand when it comes to accepting that responsibility head on.