Same video, two movies. Presentation, pace, timing, narrative all designed to reinforce your existing biases, even if you aren't aware of them. You look and think you've seen. You're nudged and put into a bubble with people offering up comments that validate and verify what you think, and what you know, and what you believe.
Anything outside your bubble is framed as a conspiracy theory or the ramblings of deluded, even evil people on "the other side".
The media streams you watch end up being a rorschach test - carefully crafted and deployed to different bubbles, A/B tested, cynically manipulative and deliberately framed and intended to evoke specific reactions. The language is carefully used so two people can watch the exact same clip or newscast or soundbite and hear what sounds like a reasonable reinforcement of what they already believe. Sometimes things will even technically be 100% factual, but it'll be just as manipulative and as much of a "lie" as if they'd made it up entirely.
I don't think bubbles is the right paradigm, anymore - these are deep, deep pits, and every piece of media that reinforces your model, where that model is the one intended for you to have by some of the big influences, brings you another shovelful deeper, and you've got to put that much more effort in to dig your way out.
Trying to talk to anyone who hasn't worked their own way out of digging out of a media pit ends up being a team sport or a tribalistic conflict - the facts and the stories don't mesh, and if you're 100% certain of your facts, and your "opposition" concedes to the facts, then you're going to think your story is the right one. The cognitive dissonance and the effort required to update your model to match reality - to recognize the manipulative, malignant influences deploying these conflicting storylines, and to figure out how to identify what actual reality is - is too much for most people, and way too much for any casual online interactions.
Not sure how you fix that without forbidding some actors from doing what they do at a legislative level, and that gets into hairy freedom of speech territory.