Cheer up.
If you're still in Sydney I'd argue that large numbers of people paddled out off of Bondi Beach because of a pervasive Australian belief that there's always a few arseholes but most people are fundamentally good and community support is better than nothing.
You likely saw a couple of extremists repeatedly tackled and then dropped by the public and police, and near real time running in to help victims.
That's somewhat contra to the bleak of "humans are inherently evil".
Maybe the message of Lord of the Flies was that nuclear weapons and the Cold War depressed at least one author and that boys need mentors.
Maybe it's an issue in general with the On the Beach genre, from Shute to Winton: https://theshovel.com.au/2025/08/20/tim-winton-wonders-why-n...:
Don't get me wrong, I don't think humans are inherently evil. In fact in times of crisis (like the one you mention) we do tend to come together and I think that's evidence that the belief is incorrect.
I just had a discussion the other day with somebody who outright told me that they think humans are inherently evil and must be managed under a system to keep in order. I don't think it's an uncommon belief and nor do I think it's a bleak world because that belief exists, it's just a mistaken belief.
I would argue that you see the belief raise its head far more when people are interacting with others who they don't consider in their "in-group".