Could it be that the connection between like-minded people is the problem?

Until this century, people lived in a social world constrained by geography: your family, neighbors, and friends were the people physically present around you, an accident of geography rather than one of interest. The people around you might well not have shared many of your ideas, and that friction kept you in check just as you inhibited them to some extent. Nobody you knew went out in public dressed like a dog or advocated for the disenfranchisement of people who eat peanut butter because you and his other friends would intervene, telling him that those are crazy views.

Now, with the internet, your crazy friend can shun your inhibiting company, lock himself away in his house, and spend all his time on fora and discord and corners of social media where people share his views. His like-minded friends tell him that dressing as a dog is fulfilling his Dog-given identity, and that the peanut-butter eaters are committing genocide against his own like-minded people. Without the inhibition of friends drawn from the accident of geography, the man who surrounds himself with virtual e-friends in a social media echo chamber thinks that the crazy ideas he hears online are normal.

Maybe the inhibition we get from socializing with people who don't share our interests, that friction of dealing with people in real life, keeps us from sliding into mental illnesses and political extremism that spring up when we get nothing but validation from people who share our interests.

This is my theory too. The internet made it easier to connect with diverse cultures... and then ignore all of them in favor of the one that agreed with you on every point so you could ignore anything that went against your thoughts

Yes that's true. Everyone gets to interact with people that are closer to their ideals but it makes society less homogeneous and disconnected locally because there is no geographical grouping.

At the same time people are more mobile than ever because of technological, opportunity and work reasons as well. So, there is a lack of real grounding. Why bother being friends with your neighbors or local people when you can just travel for not very long and visit people you prefer?

It leads to tensions because people live close together but have a very different way of life and sometimes radically different values, even in close quater communities. They end up hating each other secretly because without communication you cannot even begin to empathise.

The social media groups reflect that; they are an echo chamber to cry about people and behaviors you don't like and reinforce your own opinions, behaviors and their superior validity.

There is also the part where large government of the providence state are to be blamed for favoring rampant individualism. Instead of having to deal with friends and family you deal with soulless corporation and obtuse bureaucracy to get your needs met.

When 50 years ago you could drop by to see your doctor, now you call a number, a robot answers and gives you an appointment in one month. It's not just social media that is to blame it's just technology in general that has allowed and basically created a massive bureaucracy for everything, pretending to focus on making things efficient when it basically only consumes value and is just a means of control/surveillance.