I'm from a country where the TV and state are highly colluded and social media has come as a welcome alternative. Moreover, are these "polarization issues" the USA currently experiencing a product of social media, or its own cultural problems, surfaced by social media? You're not the only country on Facebook, remember that.
Also, I'd rewrite your opening rhetorical question for clarity:
Was TV, as a homogenizing force that entertained and dumbed people down to what big-money publishers wanted them to believe, a better alternative?
I'm from Mexico. A good example to look at is Carmen Aristegui. She's an award winning journalist, most recently named one of the world's greatest leaders by Forbes, but she's been shunned from most traditional media outlets. After she reported on a corruption scandal involving the president she was fired from the broadcaster she worked for, and has since relied on web/social media to keep doing her job.
Meanwhile Televisa (biggest TV network in Mexico) reports memes [1], random crazy people [2], and is known to be very politically biased [3]. No award-winning journalists on TV.
[1]: https://www.youtube.com/watch?v=Dl1XceNu-LE (this girl's XV birthday became a big meme in Mexico)
[2]: https://www.youtube.com/watch?v=ObV9XDBLRUk
[3]: https://en.wikipedia.org/wiki/Televisa#Criticisms_and_contro...