I know it’s cliche to blame the internet, but ... the internet is a big factor. Previously, there were only a handful of big media outlets that everyone read/watched, they kept decently to journalistic integrity principles, and made some effort to be balanced and not overly biased. No OANN or Newsmax there. But the internet allowed anyone to be a “journalist”, and as fringe media started to gain in popularity, mainstream media started getting more polarized too, to keep market share.
Going back further, before the existence of mass media, everything was more in-person/local. When you have a small community of people you talk to in-person, you’re going to be way more reasonable than on some global, anonymous, online community. Social media is a great example - it’s a breeding ground for arguments, conspiracy theories and extremism. People who would be perfectly civil to each other in person can be absolute assholes to each other online. How many email/Slack disagreements have you been in at work that instantly resolve the moment you move to in-person or video chat?
Some will say this polarization always existed, but I do feel it has gotten significantly worse. I don’t remember the 90s feeling this polarized, with people so unable to agree upon basic facts about current events. And I’m guessing the 90s were more polarized than the 50s.
One good thing - hostilities BETWEEN nations seem to be decreasing. I don’t think we’re on the cusp of World War 3 or any such thing, but hostilities WITHIN nations seem to be on the rise, at least from my “gut feel” view of my life so far.
On that note, life has been good for a long time in the west. War is an absolute atrocity, but it does put petty disputes into perspective, and build some sense of national unity. Since World War 2, life has been pretty cushy and safe in western democracies, so maybe we’re starting to make enemies of each other to fill the void?