I fear you misunderstood me. Fascist would be if choice would be forbidden, when everyone would have to always hear every side of every topic.
Even with newspapers and the like are filter bubbles possible. I am free to buy only the newspaper who writes the stories in the way I want to read them. There are left wing newspapers and right wing newspapers and stuff in between. And even with newspapers and broadcasts you are still free to only consume what you want to consume and block, by not buying or active ignoring, what you not want to see or hear. Things like cracker-barrel philosophy or Stammtischparolen where a thing long before the Internet.
Echo chambers are a normal part of being human, it exists in small (only between friends),huge (tribes/nations/cults/religions) and anything in between more or less as long as humans are able to communicate.
I never said that they are a good thing, I say they are a natural occurrence, something that only can prevented by a very dystopian system.
Because people will always filter what they want to hear and consume, and with that create filter bubbles. If you went to church (regardless of the specific religion) you enter a filter bubble. If you talk with people on a rave you are in a completely different filter bubbles then in a country music bar. Filter bubbles are all around us and yes the Internet is, by its nature, a magnifying glass for this effect. But it inherent to the human nature not inherent to the Internet. So to prevent filter bubbles you would have to radically change the human nature.