the question seems to make the assumption that large infrastructure projects would be desirable or necessary in a world without institutional hierarchies. which implies the persistence of mass (and i mean mass) society.
i am not sure that maintaining mass society is possible without the institutional hierarchies that co-created/co-depend on it. so i think the question remains in the realm of (accepting) the status quo, rather than questioning what creates and underlies that status quo.
syrphant, in your last example, one can take a point of view that both a) and b) occurred. one can feel a sense of connection and shared accomplishment and a sense of individual accomplishment. i don't see it as an either/or situation.
i disagree with your notion that your goals were distinct ("you moved your side, i moved mine") because as you both move your sides of the table, you must adjust, balance, steer, make eye contact with another, feel and sense the combined movement of your efforts, etc. as you move with the other person....much different than each lifting and carrying their side independently of the other. you also share the goal of moving the table from one spot to another.
edited to add....
tthe idea of "deserving praise and pride" doesn't resonate with me. "deserves" according to who? it sounds as if some authority exists which determines who deserves something, and who doesn't. the word "deserve" itself smacks of authority to me.