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

[Lauront]

Nope, it's all aether lol. Job crystal? Aether. Monk Chakra? Aether. Drk abyss? Aether. Memory and emotions of found in battlefield (relics)? Aether. Limit break? Aether. Echo? Aether. Hell, even summoning primal via prayer and faiths, which funny enough should be a dynamis thing, is actually aether based somehow.

Aether is like the Force of ffxiv, but can be scientifically measured and studied. Meanwhile dynamis has never been hinted before EW.

Yup, they were listed in this. They're extracts from Encyclopaedia Eorzea, which are in-world knowledge compiled by Sharlayan scholars - like you say, they have ways of measuring and even visualising aether. They will probably avoid a retcon and say the LBs can be fuelled by either/or (and in Elidibus's case it very clearly is prayer fuelling him, which raises further doubts about the inability of an ancient to wield it, albeit via workarounds), but in any case they've had that lore for a long while. The other thing typically brought up as foreshadowing is Omega, but I find that one particularly weak as an example, because it's a soulless construct created by beings that themselves lost their "essence" by digitising their minds and bodies to become robots. So there's already that massive differentiating factor with the main character.