> I think it’s simply because it has been a while since disease and pestilence was a worry for the average Western country so the average citizen (and therefore the leaders) are complacent in a sort of “It can’t happen here” way. There have been outbreaks such as the AIDS epidemic or swine flu but nothing as impactful, infectious, and at the scale of COVID.

I agree that this is the main factor. Consequently I proposed the concept of the "civilization immune system" to explain how it works: https://www.sonyasupposedly.com/civilizational-immune-system...