Endwalker's message (spoilers!)

[Rinhi]

b) Meteion killed most of those civilizations herself.
If a is true ... wow, someone at Squeenix is a MAJOR pessimist. And if b is true ... it's a big universe. If one single person can end it that easily, why hasn't it ended long before now?

I don't remember if it's straight up said or strongly implied, but Meteion could also influence the emotions of others iirc