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

[Lauront]

I fail to see where in the context lies that us as the audience were supposed to be see Venat as this "antagonist" when all this time we've been helped by her blessing numerous times in our endeavors. The most we get in terms of questioning were her status as a "primal" and in the context at the time we assumed that all primals were bad news considering their nature of sapping away aether from the land and tempering people into mindless zombies who do nothing but worship them. Yet none of those qualities applied to Hydaelyn herself as:

1. She being the mother crystal, didnt cause any danger to the world by siphoning aether.
2. Tempering? I suppose her giving us the Echo and the Blessing of Light is a boon, but not once did our character nor any other of the WoLs went around worshipping her mindlessly or act out of their own volition; traits that reflect one from being actually tempered.

The setup that was established with Venat/Hyadaelyn during the end of Shb was mostly just "what exactly are you, and what is the grand plan here"

You're conveniently forgetting the part where the entire scene in the Word of the Mother is essentially her lying thanks to what we learnt in SHB (and really, in EW this isn't even disputed), and that she essentially willingly went against her people, the ancients, and sundered (=genocided) them (the question being if it was accidental or not)? The 3.2 art with her wrapping crystalline chains around Minfilia? The suggestion based on Elidibus that becoming the heart can take a toll on that individual, as well as their memories, and thus she may be similarly affected? And how the WoL, as soon as he meets her incarnation as Venat, in EW, is sceptical of her? Or how Y'shtola and Krile began questioning the reasons behind her inaction?

BTW she never granted the Echo. She can awaken it, but it's not hers to give; it is an inherent albeit fragmented trait of the ancients, awakened through the right events.

A character benefiting the protagonists scarcely implies they can't be or become antagonistic. It's not really a good argument.

There really wasn't much of an anti Emet-Selch/Ascian crowd. If anything, people felt bad for having to kill the guy and doom an entire race.

Hmm I remember rather differently.