Tony, you are correct in describing how human nature and business objectives form information bubbles. But the underlying cause is in the editorial policy of propagating this or that truth. That approach boils down to rewarding one set of views and censoring everything else.
Please acknowledge that most major media outfits follow that style. BBC still tries to stay objective, but even they do not dare to question some ongoing mantras. But BBC TV is at least one level of magnitude better than any American TV news.
Will the open format which aims to find the truth be perfect? Never. Nothing that people do will ever be perfect. But it might be better what we have, and it might be good enough to make a difference.