On an individual level, you can combat the polarization of politics by following people who post strong and eloquent arguments against your ideological position,
or just not using social media as your only source of news
i think the "filter bubble" was actually much worse pre-internet when most people only read one newspaper and watched one news channel btw. imo the bigger issue of social media is something else the article touches on: it's extremely easy to spread propaganda and astroturf debates. people haven't developed immunity to those things the same way they developed immunity to more traditional one-to-many forms of (political) advertising. i.e. people are very likely to believe things shared by their friends on twitter or fb.