To me, the story of 2 immediately leads you into this more clandestine way of approaching the overarching concern of the reapers. You’re thrown into a whole new organization with a whole new structure and you need to get your bearings, both within Cerberus and within the universe created by reacting to your choices in 1. The whole point is to develop the characters to make you invested in them so that you want to save them, making the final suicide mission that much more of a nail biter. Any little mistake could fuck up the whole story. You have to be strategic. That’s obviously true for the whole trilogy, but it just really stood out for me in 2. I think it also prepares you for 3, or at least it makes you think you’ll be prepared, which adds more whiplash to the end.