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

[Lauront]

Although LBs aren't confirmed to be a dynamis thing, it's worth noting Elidibus can utilise them as a primal, and go over and above that by blocking them. If they do confirm that to relate to dynamis manipulation, the sheer amount of prayer which resides in a primal and the changes it causes to the individual may have something to do with it (and it'd further raise questions as to the logic of sundering mankind to manipulate dynamis... which in reality, as noted by others, seems ancillary to her real aim, i.e. ensuring suffering wasn't absent, to avoid the supposed trajectory of the Plenty.) I suspect it'd be difficult to tell even if she could, because on some level it is ultimately just a fuel source, albeit affected by emotions.

Also, she confirms she's sundered in the Word of the Mother scene as well. My guess is that because she's still inside the primal but acting as its heart, the exact mechanism of it is different to how it affects a "regular" ancient and instead parts of the primal are segmented while the heart remains on the Source.