What's the point with that quite lackluster story in Endwalker?

[TaleraRistain]

This does raise a very important question. What exactly happened when Venat sundered the world? Did all the current inhabitants just pop out of existence or something? Did it cause 14 umbral calamities at once or was it a normal day?

If I remember, Emet explained that outside Amaurot in ShB. When a soul is sundered, a copy (a reflection) of the being is created but it doesn't have the same memories. I'd have to look at that cutscene again, but I never got the impression it was wiping anything out of existence.