In the USA, I'd be more ready to place more blame on the binary political parties, as well as the mainstream media. The internet will eventually greatly reduce the power and influence of all three of these. What we're witnessing now first-hand is these three power-holders collapsing and screaming "But...But...we're still very relevant. Look! Look!! You need us to protect you from 'them'" (with 'them' being one of the other power-losing enties). All three have become terribly efficient at using hype, hyperbole and divisiveness as means to "proving" they still matter.
For more info on these concepts see "The Influential Mind" by Tali Sharot.
While she doesn't do a direct take down of media, social media and politics, it doesn't take a genius to read between the lines a bit and extrapolate her science onto the current state of things.
This is true, but its worth acknowledging that these apps are purposefully built to be addictive . Things like endless scroll, pull to refresh, like buttons, gamification, and more have been developed to make that mirror more psychologically compulsive.
And doesn't that described the major of people on social media? They don't understand cause v correlation. They don't understand subjective v objective.
Getting off of social media didn't make me a better person, but social media definitely made me a worse person. As I mentioned elsewhere, I jumped from reading two books a month to six. Those extra four books a month are making me a lot happier than the equivalent amount of cat videos and fighting with my fellow Democrats about which of our candidates sucks the least. The additional time playing guitar is making me a better guitarist, something I should value a lot more than snopesing the latest political quote meme. Going to bed earlier is better for my health than staying up another hour endlessly scrolling because I'm too tired to stop.
Alcoholics don't stop being alcoholics, but they can stop drinking, and stop subjecting themselves to the countless problems alcohol was creating for them. That's how I feel about Facebook. It created real problems for me, and when I quit, those problems have gone down.
Most people consciously think they would prefer to associate with people they "identify" with. In real life you don't have much in the way of signaling so this process was not especially efficient. And that was a great thing. It meant people who had completely different worldviews would end up becoming friends, and having some fun if not heated debates at times. And most importantly they also kept each other tethered to reality. Enter social media. Now, no matter how extreme a group you "identify" with, you can find millions of people fitting that. And people utilize this to filter people down to just these people.
But this filtering now tends to drive divisiveness in two big ways. The first is that as people lose contact with those they do not "identify" with, it creates a dehumanization. The other issue is the even bigger one, and also contributes heavily to the first -- people lose touch with reality. Imagine the answer to a problem is 0. You have one group that insists it's at least 20, and another that insists it's at most -20. Now all the 20+ guys join together. And now thinking it's 25 is really kind of moderate - literally nobody thinks it's less than 20 and lots of people even think it might be in the 30s, or higher! Their collective starts going further and further up. Next thing you know the average is 30, then 40, then ... And vice versa for the other group. This likely a similar process to how you get from 'dress modestly' to 'wear opaque black sacks that cover everything including the eyes.' It's a homogeneous collective raging on in who can be more virtuous (by the standards of the collective) without any sort of counter-balancing force going "I LOVE BIKINIS! Live free and natural. Nude beaches are what we need!"
But the key point of this all is that this filtering would be impossible without social media. I completely agree that the media is contributing heavily to this, as well as politicians, especially those who play into identity politics. But on the other hand, I think their behavior is arguably more of an effect than a cause. In a divided world, the way you make money with things such as media is not by walking the line, it's by jumping off the deep end one way or the other. And similarly for politicians. People actually get angry when people in any way work with "the other side." Consider the outrage that Musk would dare work on a presidential advisory board where he would actually have a voice that'd go straight to the president.
I would add one thing, though... in the days before social media, but also before near-instant transportation and tv and stuff, people lived in geographically isolated communities. While there wasn't cultural self-selection, your culture was selected for you, and almost everyone you knew was like you.
This is reflected in politics as well. Urban areas are necessarily more socially diverse than rural areas. If you live in a big city, you rub elbows with people different from you every day. You learn to be tolerant and respectful of social diversity just for your own sanity. Homogeneous rural communities don't learn tolerance, because they don't need it, and it's arguably a hindrance. So we wind up with socially tolerant, diverse liberals, and socially intolerant, monoculture conservatives (not passing a judgment here). It's a result, not a cause.
Social media exacerbates both these tendencies... on one hand, it's so easy to build purist echo chambers, which lead to holier than thou political one-upmanship and drive extremist views. On the other hand, we're constantly exposed to people wildly different to us through friends-of-friends. That's a lot of cognitive dissonance. Rather than leading to more tolerance, it's leading to uglier forms of intolerance.
Those are also just different mirrors. Social media is a greater number of faster-responding mirrors, but the concept remains the same: the content reflects the desires of the audience.
I place all the blame on individual users. They are the ones that must alter their behavior. Each individual must come to understand how they manipulate the content they see. I don't blame talk radio and facebook for turning my aunt into a crazed right-wing conspiracy theorist (the really bad type. She believed pizzagate, probably still does.) She has done this to herself and only she can dig herself out of the hole. The family can support her, as one would any other addict, but the individual must want to change.
That said, that should not let leadership off the hook. For those three mentioned leaders to abuse their power __at all costs__ in order to maintain their power can not and should not be discounted.