The history of journalism is written by journalists, often in a self-serving way. You'll be hard-pressed to pinpoint the purported golden age of impartial truth-seeking. Early newspapers in the US were often owned by a local railroad tycoon and published hit pieces about his opponents. From the 1960s, this morphed into a way to broadcast the ideological consensus of East Coast Ivy League graduates. Some of their ideas were good and some were bad, but every single day, this consensus influenced which stories made it to the front page and how they were framed.

Weirdly, I think this model was beneficial even in the presence of bias: when everyone read the same news, it helped with social cohesion and national identity, even if the stories themselves presented a particular viewpoint.

But now, everyone can get their own news with their own custom-tailored bias, so there's no special reason to sign up for the biases of Washington Post or The New York Times unless you want to signal something to your ingroup. I don't think this is as much Bezos' fault as it's just a consequence of the internet evolving into what it is right now: one giant, gelatinous cube of engagement bait.