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

[Brinne]

I mean, my fundamental objection would be the very premise, especially after Shadowbringers (not that it wouldn't be bad anywhere, but Shadowbringers explicitly went out of its way to humanize these people - they're hardly LotR orcs or such), of trying to "justify" the genocide to begin with. When you're asking "how do you justify this genocide?" in seriousness, I think it's likely you're already probably heading down the wrong path, as far as storytelling goes.

And of course, I'm sure we'd agree that the idea of "the Ancients can't accept death" gets very tripped up in the particulars of the storyline, such as their ritual ABOUT "accepting death" having the expectation of being met with horror from the audience, or Venat's motivation centering around her being unable to accept the possible end of her world, in the far future.