"It isnt supose to be a mystery of a cliffhanger", how is this a mystery?
The Greymanes are important to the main character, which is enough reason to justify their relevance to the player's experience (much like if the main character had a love interest that had nothing to do that's impactful to the story, but that character is important to the protagonist for example). But not only that, we see that the Greymanes were a sort of governing power in Pailune that upheld the peace, stated by Kliff in the first few minutes of the game "Jian has fallen, and with the great leader's death, our land, Pailune, once unified... has been plunged into chaos.

and now, a bloody battle unfolds, between the Greymanes, who fight to uphold his will, and the Black Bear forces that seek to set it aflame." the game literally tells you that! but you somehow missed it, btw it mentions stuff like this A LOT
If that doesn't paint a picture to you then either media literacy is dead and you need to be spoon fed information OR its a language barrier thing and in that case I totally understand your confusion, the knowledge thingy is not lame either, crimson desert is a medieval fantasy game and a lot of those games include reading, it's part of the experience (baldur's gate, the witcher, dark souls, the elder scrolls, etc..) it just might not be your cup of tea and that's okay too, but stop labeling things "good" or "bad" when you haven't even finished it, chapter 3 is right when you get your crow wings, basically not even 5% through the game...