The “pretending to be wise” answer is that it’s easier to deal with mass extinction than with individual mortality; that the thought of your own death is weakened by the thought of gigadeaths.

More seriously, though:

Major disasters have always been a large part of human cultural experience. Cities have been destroyed by earthquakes, volcanoes, or hurricanes. Within recorded history, plagues and famines have reduced prosperous civilizations to desperate stragglers living in ruins.

Preventing or surviving disasters is, therefore, one of the most important things humans can work on. Disasters loom large in our cultural consciousness because they really are large and because we can actually do stuff to make these problems less bad.

Disaster preparedness is, in fact, no-kidding, really important for you, your family, your city, your country, and the world as a whole.

Preventing avoidable disasters, including manmade ones such as nuclear war, is a major part of what makes world politics morally significant. Avoiding the devastation of war is a really good reason to get good at politics, diplomacy, peacemaking, mutually beneficial relations among peoples; and the high stakes of “shit, we could actually kill off humanity if we fuck up politics too badly” is a pretty good motivator.

So … we think a lot about bad shit that could happen, because bad shit really can happen, and we can do something about quite a lot of it.

My guess would be that it’s simply because we are aware of the concept of extinction and have watched as other species have gone extinct. This causes some existential dread, like learning about death might.

We have only recently (in terms of the length of history) entered an era where we can produce weapons capable of eliminating our own entire species. Wouldn’t it be weird if we weren’t thinking about that?

It’s pretty ironic that the actual mass extinction that’s currently happening is not really acknowledged by most people.

One possibility: It is a weird case of “this moment in time is special because I am alive”.

Humans have been around for thousands of years but I am alive now. I cannot think of what the world could be like without me so therefore the human race must end in my lifetime.

This in not a new occurrence either, there have been “end of the world” groups in almost every generation in history.

List of dates predicted for apocalyptic events

It is worth noting that people always think the apocalyptic event will happen within their lifetime.

The only real difference now is that the end of the world is now caused by humans via nukes or destruction of the environment rather than supernatural forces.

Because you live in a society shaped by a Millennial Doomsday Cult. The world is ending.

(no, not ‘the’ millennials, like the generation thing)

Eh I don’t think we’re obsessed with it, it’s more just like the likely outcome due to human nature. Largely pushed by:

• greed
• differences
• And only asking “could we” and not “should we”

The end of the world has been a recurring theme in many human cultures across millennia.

AI and nuclear holocaust are just modern takes on an ancient tale.

Because when the world is about to end it’s an excuse to not try at life.

I don’t know anyone who even thinks about it, much less is obsessed with it.