I really wonder where this idea that the world was less polarized before social media is coming from. It's not even 100 years ago that we had some of the most extreme ideologies in history taking hold all over both Europe and the USA (fascism, socialism, and others). People literally went to war over these things. Another ~100 years before that, French people were cutting off the heads of their ruling class, and setting prisoners free.

If anything, social media has inspired far too much passivity in our societies. People feel relieved that they could vent their frustrations online, instead of taking to the streets and seriously threatening some of the power of those putting them down.

Also, a big part of why the elites of society dislike social media is the huge democratizing effect that it has had on information. Of course, not so much in the more authoritarian societies where our leaders were hoping for this effect, but in their own backyards. The biggest example of this by far is the information about the Gaza genocide - that is presented at best equivocally in the mainstream press (with some exceptions like The Guardian), but that was clearly visible on TikTok and other social media. This led to perhaps the single largest policy conflict between the vast majority of the population and the vast majority of government elites in the current day EU.