The original ME had one, if not two, novels with back story to the universe before the game was even released. I read the one about how Saren found Sovereign and that got me really stoked for the game. Nothing like that for Andromeda that I know of. Story was everything in the previous ME games, it feels less so with Andromeda and as you say, that makes the game pretty generic.
Good point about the novels, those were great. There's actually a novel coming out alongside the game, called Mass Effect: Nexus Uprising. Hints that there's unrest on the Nexus. Guessing that leads to the races all going their way and setting up on different planets. That doesn't really appeal to me much tbh, but we'll see how it plays out. Came across a pretty interesting theory, that would interesting if done right:
But it's all guess work. The game is out month and I feel like I know nothing about it still. Best to wait for the reviews at this point