Before, your bubble usually was the people around you, physically. You had network news and the newspapers for your information. You could read books about other countries and systems. If you had cable, you could watch the 24 hour news at the time - Cspan and similar things.
The bubble has simply shifted and become slightly more obvious.
Which really disappoints me. I was all hopeful that the internet would broaden people's bubble, but that was 20+ years ago.
I'm not sure if we did, but we didn't forget that they exist. We focussed so much on publishing facts (and rants) on social media, instead of talking to the people directly.
There are zero Trump supporters on my timeline, everybody is shocked and horrified. I would bet that there are people out there who have a diametrically opposed timeline with zero HC supporters. We need to get those people together instead of further alienating and separating them by "better", more personalised and targeted algorithms.
Strange, it's been the opposite for me. Social media has revealed to me diverse political opinions from friends that I never would have known about otherwise.
We don't reach people that are different, neither do their voices reach us. We are all so connected nowadays and yet so separated.