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

[Turtledeluxe]

The question in that is "you did this to all living things", which again confirms it was a general attack. Although it had many effects, the target was Zodiark.

Again genocide would be doing it because she is targeting due to race or ethnicity, or even people with specific aether density perhaps. But the sundering affected all aether density of everything. You can't even really invoke eugenics here because she didn't target human reproduction but aether levels.

Even in real life genocide is applied with regards to intention to harm, oppress etc. I'm sorry you feel how you do but Venat's intentions were oriented around long term survival and the preservation of the star. It's another disqualifier. This is why I've said since the beginning intention matters. She didn't reduce aether levels across the star for some nefarious reason.