Ancient civilizations probably mysteriously died out because they became so advanced they realized what they were and just couldn't anymore.
The thing with ancient civilizations “mysteriously [dying] out” is often less spectacular - it’s not a singular event, but more that maybe crops fail for a couple years, while some sort of pandemic devastates cities and collapses more centralized economies, so people gradually spread out.
Like, it’s almost a process with multiple factors. Not usually just “whoops! time to officially end Mayan Civilization™”
Just look at the history of social media platforms.
If you generalize the term "civilization" to be any sufficiently large group of people who have some sense of shared purpose or identity you could include gaming communities or even forums too
Things usually don't just explode all at once though ofc sometimes there is abrupt change that causes a community to decay rapidly
Is this a shower thought or a bong thought?
You guys have no clue how much time I spend in the shower.
It's usually the pre-universal subspecies that exist between worlds we evolve into that are planting the secret essence of humanity inside us so it can grow , they genetically engineered themselves so it's the only way they can reproduce, It grants them immortality but they must sacrifice one of there own ancestors one every hundred years or face a temporal paradox, they usually harvest a civilization every couple thousand years so they don't have to keep coming back.
Apatheosis