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

[Lauront]

All this talk of Venat/Hydaelyn being genocidal. To be frank those that survived the sundering were just as bad..

Which is acknowledged - albeit with the caveat that they are doing so to reverse the very act she performed in the first place, while failing to give them a proper explanation of why, so much so that they saw it as their duty to restore both the star and their people. Yet few of us would say the rejoinings not genocides in their own way. The fact that she is genocidal, though, is often brushed under the carpet or contested, even to the point that it's claimed that the sundering did them no harm and just "created more life".

Do we want to argue whether Hermes was special for his knowledge of celestial currents again Lauront?

You can repeat it until you go blue in the face. It won't change the fact that it is not he alone who is credited with the design of Zodiark. Worse comes to worst? Strip mine any pertinent knowledge from his mind. He is a criminal at that point anyway.