American government seems very concerned with terrorism. It also generates a lot of revenue which in turn produces political campaign contributions.
Do you really have less worries in Australia? I’d argue since it’s your homeland, you are simply used to the things that non-Australians would find worrisome. I don’t worry about medical bills (I have health insurance,) not concerned about ever being homeless, don’t consider tipping to be something worthy of worrying, etc.
And despite growing up in a rough neighborhood, I’ve never really worried about being shot.