I think the key difference is whether people mean it literally or metaphorically if they say that something is an "existential threat". Inequality and oppressi

I think the key difference is whether people mean it literally or metaphorically if they say that something is an "existential threat". Inequality and oppression and war and climate change and surveillance states and slavery and all kinds of other things may result in a dystopian future, but all those are obviously not literally existential threats, as humanity would keep existing, only in fewer numbers and much worse conditions. On the other hand, there all kinds of events that are much less likely than those former ones, but are literally existential threats for humanity - like major asteroid strikes or the worst case scenarios of stronger-than-human AI, or perhaps some pandemics or nuclear war might cross that threshold iff they can wipe out all of humanity, not "just" most of it.