I suppose the subtlety is that people want to be angry if (and only if) reality demands it.

My uneducated feeling is that, in a small society, like a pre-civilisation tribal one where maybe human emotions evolved, this is useful because it helps enact change when and where it's needed.

But that doesn't mean that people want to be angry in general, in the sense that if there's nothing in reality to be angry about then that's even better. But if someone is presented with something to be angry about, then that ship has sailed so the typical reaction is to feel the need to engage.

>in a small society, like a pre-civilisation tribal one where maybe human emotions evolved, this is useful because it helps enact change when and where it's needed

Yes, I think this is exactly it. A reaction that may be reasonable in a personal, real-world context can become extremely problematic in a highly connected context.

It's both that, as an individual, you can be inundated with things that feel like you have a moral obligation to react. On the other side of the equation, if you say something stupid online, you can suddenly have thousands of people attacking you for it.

Every single action seems reasonable, or even necessary, to each individual person, but because everything is scaled up by all the connections, things immediately escalate.

If people are bored, they’ll definitely seek out things that make them less bored. It’s hard to be less bored than when you’re angry.