Perhaps people throw themselves into heated polemics to give content to their lives, to warm their hearts.

From Sparks: Eric Hoffer and the art of the notebook by Tom Bethell.  One of Hoffer's observations is:

POLEMICS GIVE WARMTH

Perhaps people throw themselves into heated polemics to give content to their lives, to warm their hearts. What Luther said of hatred is true of all quarreling. There is nothing like a feud to make life seem full and interesting. 1950

Seventy-years later and with the always-in, always connected, social media rich internet, we can see that the technology has changed but the human motivation is the same.

With a caveat.  In 1950, even in prosperous America, everyone was much closer to the financial margin.  We are astonishingly wealthier, healthier, live in bigger houses, with more things than ever in history.  Your average American today lives a safer, healthier, richer and more comfortable, life than any medieval monarch.  

It used to be fate and circumstance forced existential, life-and-death trials and tribulations on us with great frequency.  Mere survival gave life meaning.

The further we pull away from that dangerous frontier where survival is a real question, it seems like the more some people are disposed towards meaningless quarreling in order to give meaning to life.  

It is notable that the friction created on social media is at such variance from real life.  Pareto distribution is everywhere.  Only a small percent of people use X (or any social media platform) and only a small proportion of those on the platform generate most the content, and most that content tends to be self-created quarreling.  

Not only are people safer and more comfortable but at the same time we have created a mechanism for them to create the quarreling cantankerous environment (think BueSky) that creates a simulacrum of meaning.