I guess aspect powers mostly raise the power level? But yes, the lore is incomplete enough that we don’t have any actual statements on it ingame. Maybe there are some in the two dragon-centric novel, the new one or the old one, I wouldn’t know, but I doubt it, since wowpedia doesn’t seem to know more, either. I guess they were shown to be weaker than the Incarnates would be something that the random powerup would change that? I don’t have any more than that.
Just as I have no idea why they made the “oathstones” to be the highlight of the zone questing, without explaining them to us… I guess they were meant to help the aspects get their powers, but now they don’t need them, because they got them another way? Or maybe Azeroth wouldn’t have empowered the dragons, if they didn’t empower them before? Who knows. It’s just the main plot, it isn’t that important, is it? I mean, DF is just going to be the next starter addon that every new player will level through, why would it have to make sense to someone who isn’t steeped in oscure sources and fan theories?
What did the main antagonists, the mortal primalists, want again and why? Erm, power. It’s power. Always because. And they hate dragons for some reason. If that’s not compelling, I don’t know what is.
At least they got the time travel story right, where Nozdormu was saved from being turned evil in this timeline by… travelling back to the past, and stopping the bad guys from… changing the timeline so he’d be bad in the new timeline?
So yeah, maybe it is that bad. Though not all of it, I guess. The blue dragon quests were (mostly) nice and irrelevant, the Black Dragon family drama was kinda nice, as long as it lasted, the Dracthyr had hints of a passable story and the ressurection of Tyr was fun, once it got some mortals in the quests. And I guess the Amirdrassil thing was a passable end to the Teldrassil story, which was long overdue. So… it’s not a total waste?