I don't agree that this is the fault of tech at all. Facebook et al are still largely echo chambers, where we see what we have cultivated ourselves to see. Sure, recommendation algorithms show us external things once in a while, but by and large you can cultivate what you see on social media.

The real culprit I believe, has been the incredible hysteria of the legacy media as it joined the social media spaces, and started their race to the bottom for clickbait and outrage porn. Covering inane tweets, and blowing them up to pretend that crackpot points-of-view have more weight and are more common than they truly are. Gotcha gonzo-journalism, that prides "getting them" (whichever group that may be) over informing, and in the process dehumanising large swathes of people for clicks. How you "can't avoid politics, because everything is political". Ravelry, which is a crocheting website, went mad with us-vs-them discussions. Why?

The fault is mainly with legacy media, because they had the credibility and prestige of their history, plus the consistency of their output (daily, weekly, whatever), which they used to spoonfeed poison to large parts of society. How others are "unlike us", and that "they're evil", and oh by the way, "vote for our candidate" who is the some storybook hero we need.

The "two-minutes-of-hate" has come largely from legacy media, and they are responsible for the schisms present right now.