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

[Lauront]

I saw this brought up, but the part where it's mentioned that Venat opposed Zodiark's creation is in the cutscene with the Scions and the Watcher, post-Zodiark Trial. It's a bit baffling, though, because the very same conversation confirms that Zodiark was a necessity, and that the process of coming up with his creation only began after the Final Days had started.

I want to say that Venat might have been unprepared for how severe the Final Days truly were, but that last part is a real deal breaker. And it's too hard to believe Venat could be actively witnessing the death of Etheirys and go "This is fine, we don't need Zodiark".

Correct, that's the scene I'm referring to - coupled with the fact that it's not worded that way in the FR version, I can only wonder if there was some confusion between Azem, who was stated to have left over the issue (and now I wonder if this was encouraged by Venat given her knowledge of what would happen), and her faction's opposition (which in SHB is stated to occur before the third stage of sacrifices), which survived into the MSQ writing. But like you say, it's flatly contradicted by the Watcher's following lines. Very strange.

I also agree with your take on Venat - my issue is more with a lot of the writing surrounding her, including them making use of time travel yet again right after SHB (in ways that IMO constrained her own agency), and the potential use of this to explain mysteries like why the three unsundered escaped the Sundering. I'm reserving judgement until I see if they have any commentary on it to see what to make of it but overall I wasn't very satisfied with it. I would've liked the ability for a dialogue option to at least have my character distance themselves from her actions and refuse to condone what she did to the ancients. Acknowledge they (the character) benefited as a result but at a terrible cost to the ancients. Something to convey mixed feelings. Overall, I get why people dislike her, but a lot would agree this is due to what they see post-Elpis, so how they wrote it seems to be a culprit - bending over backwards to try paint her in a good light when it's not that simple. I think this poster put it very well:

People tend to have a disproportionately negative response to controversial components of media which offer no room - within the text - for disagreement, because it feels like the writers are demanding you abandon your values and accept their own, or else become an 'unwanted reader' for whom the story isn't for. If you've been around fandom circles for long enough, you'll know this is the soil from which a lot of big discourse storms sprout. People might hate characters who are framed more ambiguously, like Emet, but the narrative being mixed in terms of how he's presented serves as a release valve for the reader-author tension, letting people feel like they have permission to draw their own conclusions (though admittedly, Endwalker was also unkind to outright Emet haters, which is another flaw it has, IMO). But if a writer chooses to insist that a character is objectively righteous, or objectively reprehensible, then if there are people they can't bring on board with those outlooks, a lot of them will go crazy. It's the same reason people often hate hypocrites more than actual unrepentant murderers in the real world. The mind is revolted by any dissonance between what it is being told is true and what it knows to be true. (In this case, Venat being a loving goddess worthy of our love and the fact she murdered like a billion people for reasons that were presented kinda ambiguously respectively.)

I think a lot of people on the hardcore Venat hate-train are kinda wrongheaded about the whole thing, because ultimately, she's just a device. How she ended up coming across in Endwalker could just as easily be a product of the too-many-cooks and gameplay/story balance issues endemic to all game writing, or just more general messy writing, rather then the result of intentional choices by the Main Scenario Team. And even if it was wholly intentional, it's pointless to be angry at her and want retribution, because none of this junk is even real. But it's not hard to understand why it makes some people act sorta over the top. Intentionally written injustice within a story has the hope of eventual catharsis, but unintentional injustice feels like it might be there forever. People want some kind of release for their feelings that isn't just dumping the whole game.