Interesting that his propaganda model [1] actually breaks a bit with the age of internet. Social media, news aggregators, small independent bloggers and small independent news outlets don't have the described biases. Algorithmic filters are somehow unbiased. Independent person/outlet can question the government, capitalism, doesn't have to trust government's spokesmen, doesn't have to publish them, doesn't even have to make money. In a way all those "news bubbles" and "fake news" are actually anti-bubbles and make "democracy" more "democratic".
No it doesn't work that way. It's a nice theory, but I've been a mod on a national sub for a while, and I've been on forums since around/before slashdot.
You can very easily overwhelm the signal with noise. The plethora of independents means nothing if only a few of them get heard.
Matter of fact, with some pushing, you can have one "independent" dominate a large portion of the channel. At some juncture the network effect takes over and the process becomes self sustaining, you just need to play on people's/your target markets biases well.
This is a people problem, and people are getting way too good and understanding and manipulating the biases of other people.
[0] https://en.wikipedia.org/wiki/Manufacturing_Consent