Nobody seemed to have this much of a problem with propaganda back when the common man did not have access to it.
Some of the problem is youtube promoting a 'common man' Alex Jones 15bn times because he drives youtube's advertising revenue. And some of the problem is russia running active disinformation campaigns and organising competing protesters to fight in the streets.
If this happened in the 70's, you bet people would have had a problem with it.
It doesn't control how people act, but for the rest this is exactly what mass media was always doing, influencing beliefs and opinions of the masses, never able to criticize powerful and wealthy where it truly mattered. Facebook only made this space a bit more diverse, actually letting some criticism in, weakening mass media influence. But it's ridiculous to think this affected "democracy", the US isn't even considered to be a democracy outside of the US, but more like a capitalist-ruled police country.
If this was "people saying things I don't like" it would be absolutely fine. People say things I don't like on HN all the time, and I either ignore them or debate with them - which is how it should be.
But that's not what this is about. This is about political PR machines with unusual wealth lying to Facebook users on an industrial scale to control what they believe and how they act.
But perhaps you think lying to people on an industrial scale is ok?