Endwalker's message (spoilers!)

[Kozh]

Venat's actions were the only ones who would break the cycle of the Final Days. Had the Ancients been successful in recreating their paradise, they would cause the Final Days again.

Final days only happen because Hermes being stupid and dynamis being an unknown force. Supposedly Venat told everyone what really happened, I believe the Ancients will be able to prevent another "Hermes" to be born.

The reason why this would happen, is because they did not understood plight, suffering, and despair. Emet-Selch's responses to Hermes proves that they wouldn't learn. In short, the Ancients seemingly perfections would obstruct them from learning about life's imperfections. Venat knew that this would happen, as she was already more enlightened than most of the other Ancients.

They don't know suffering and despair?? Even the Pandaemonium raid show how even during their peaceful times, the Ancients aren't some sort of peaceful hive mind that's unable to perceive sadness. They still have conflicts with each other, they still feel sadness when someone they love is gone. The only difference is that those feelings are rarer compared to sundered life. But it's unfair to impose our standard on them.

Venat is "more enlighten" just because she heard about some adventures from one guy from the future, then decided the fate of the star by herself, a message that previously is deemed a bad thing by the game.

Mankind of the future was the only one who would be able to deal with it, BECAUSE they suffer. They would be best equipped with dealing with it, because they found joy and meaning in the small happy moments.

Only half true. The point isn't just "feel suffering", but because she thinks having more control of dynamis will help them fight meteion since she's made of dynamis. Hence, the sundering.

Oh, and if Venat would tell the Convocation, she would become a pariah immediately. Place yourself in one of the members of the Convocation's seat, and think about how you would respond.

Except Venat is the previous Azem, one of the convocation which was highly regarded. See how she's still respected by the other Ancients on elpis? And this is a story in magical setting when fate and prophecy are the norm. Regarding the memory loss thing, many people already pointed out that: 1) she can do the "show the past" using environmental aether like when she help us; 2) I refuse to believe that the Ancients, master of magic, can't research a spell to reverse kairos effect.

Even if option 1 and 2 aren't successful, once the final days start it will only prove her right and they will listen to her. Remember that the final days reach Amaurot last and they actually still had time to debate and research about it.