> Social media did a lot to foster outrage and destroy nuanced thinking.

Way before social media, there was short wave radio, then cable news which introduced the 24-hour news cycle, and entertainment-shows-disguised-as-news with their permanently outraged talking heads (think Rachel Maddow or Tucker Carlson).

Political polarization is older than social media, and it wasn't emergent - it was a deliberate political tactic and it worked well enough until the other side adopted it too. It's like an iterated prisoner's dilemma and both sides are now locked into a cycle of defecting - doing otherwise makes no sense, and there aren't many deescalation off-ramps.