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

[RobynDaBank]

That would be correct. However, one important detail missing from EN (but seemingly present in other versions) is just how these advisory postions relate to Elidibius. The EN text does touch on it, but it does not convey the context properly at all.

In any case, it was brought to my attention the English text actually does mention the position being available also to those that did not serve as members of the Convocation, which makes the entire point I was making moot. :P Apparently, part of my argument has been against people's headcanon instead of what's actually in the game. S'what I get for assuming people are arguing in good faith, I guess. Pretty easy assumption to make given how much of the game actually is inaccurately translated, whether intentionally or not.

十四人委員会を筆頭とする公的な役職を下りてなお生きる者と、
調停者エリディブスのみが縺える、助言者の印さ。

Yeah how Elidibus is described here is: "十四人委員会を筆頭とする" - headed the Convocation of Fourteen, "公的な役職を下りて" - retired from his official post, and "なお生きる者" - a still alive person. I don't remember how the English version described him, did it do the same?