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

[fulminating]

So your choices are Venat (and everyone else) lacks agency because the loop is self-sustaining and the future must come to exist so we can play the game OR

Venat gives the Ancients more choice than we already know she does (as it is shown), finds an alternative, and the game collapses.

There's no magic situation where Venat finds a solution and the future still persists. None. Zero. So decide what you want, either way it's problematic for Venat whether by the players choice or your story take which leads her to kill off the reflections.
.

The warrior of light dies to black rose, as the world collapses the ironworks free graham from the tower, combine the raid series and send him to the first. Crystal graham then pulls the warrior of light to the first, averting the 8th umbrella calamity with the defeat of hades. Yet crystal g’raha doesn’t die nor disappear from existence when that time line is dodged, rather surviving bodily until he turns himself into a statue, and spiritually by sticking his mind in a rock and being ferried to the source.