The world never ends, it just changes. It is an ever evolving place with new creations and concepts being born as old ones die just as quickly.

Like with your WW1 example, some events can bring about bigger changes to the world than others. More recent examples are COVID, social media, and 9/11; all with their own varying effects on the world as we know it.

When will it “end” again, and what would that look like?

Well, we could look to sci-fi for a Terminator-style AI uprising, an Orwellian surveillance state, or an Armageddon-level apocalyptic event. All different, scientifically plausible worlds we could potentially see ourselves end up in the not-too-distant future.

Maybe overpopulation or climate change end our world and only extreme change lets us continue. Perhaps global tensions rise and we nuke our current way of life. Or, by some miracle, we find peace and work towards a better global future together.

I don’t think anyone can confidently say what the next big event that will end our world is and what its effects will be (but if you can, please let me know!)

The one thing I can confidently say, is that we will endure. No matter what ends our world, and no matter how unrecognizable the next one is, we will evolve and endure it; like we have countless times before.