Fundamentally, I don't want to read about barrista!Steve and customer!Tony. I enjoy mundane situations set within the existing canon a whole lot more. Like, their going for burgers, or taking a walk, or Tony puzzling over the oven's self-cleaning function. I'm not interested in a Steve and Tony who lack the history and burdens that make them who they are. I'd read a no-powers AU that tried to translate those histories into another setting though. Might be interesting.