But increased polarization around the world isn't because of this. There's the typical environmental factors: an increase in changes (or challenges) to traditional values increases polarization; an influx of migrants increases polarization. But then there's also social media, where mastery of "engagement" by businesses for profit has been adopted by political groups looking to sow division to reap the benefits of polarization (an easier grip on power). The rapid rise of polarization is a combination of both.
It's nothing new of course, political/ideological groups have been doing this forever. We just have far more advanced tools with which to polarize.