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

[Kyohei]

And this was also after 5.4 (?) had Thancred with his line about this marking the end of primals. Apparently not, they're fine now. I don't mind that so much but then they also had the self-same characters, Y'shtola and Krile, evincing mounting scepticism of Hydaelyn, and this is all discarded without second thought, even after her story becomes more and more questionable - for example, the implication that her backup plan would damn the shards, or that she decided to lie about the entire origin of the world to enable her to focus on a decision she made on a very murky basis. Agree with the rest - and in the end, the Ascian tempering is written only so as to explain the actions of some of them 12k years later. Fine, but then why not put that to use with our benevolent mother too, being at the heart of such a primal? She is after all a supreme deity and an all-powerful being, so surely at the least she should've been tempered in a similar manner to the Convocation.

Yes that's exactly where I'm coming from, they had doubts on Hydaelyn in the end of ShB, then we start Endwalker with Krile offering herself without restraints. I don't know about others, but if I had doubts about someone I certainly wouldn't let myself freely become their vessel. Like you say, the more we get in Endwalker, the more shady truths we learn about her. Strangely though, instead of getting an even more critical eye while learning said truths, the scions' faith enhances and just become sheeps only able to welcome everything she does. It simply doesn't logically add up.
Hydaelyn certainly felt different than Venat, it would've been natural for her to have been tempered by her own ideals and convictions really. Those were so strong she obliterated her own world, but the story is trying to tell me her mind remains intact? Sorry but can't buy that.