I concede your point, but I feel like black swan event isn't a real thing if its some structural flaw that's obvious in hindsight, eg. its obvious the 2008 hou

I concede your point, but I feel like black swan event isn't a real thing if its some structural flaw that's obvious in hindsight, eg. its obvious the 2008 housing market was going to collapse, so that's not a black swan, so what is an example of a black swan then?