In Original Sin #0, Sam Alexander asks Iron Man and Captain America why Uatu does what he does.
Iron Man: The Watcher? Uatu? Uatu is as old as time. He barely lifts a finger to act... but he keeps tabs on everything everywhere. He records and studies the activities of a billion billion races. Nova: How come? Beat Nova: I mean, I understand what he does. But why does he do it? Is he studying for a test? Is he selling information to advertisers? Is he looking for something? No one studies that hard unless they have to. Surely he's got some purpose. So what is it? Cap: (After a longer beat) You know... I don't think anyone's stopped to ask.
A few of the introductory captions are blackly funny:
The Punisher: World's most successful mass murderer.
Moon Knight: Fist of Khonshu. Possibly psychotic.
Dr. Bruce Banner: Not to be made angry.
In Original Sin #2, Tony Stark and Bruce Banner are in Avengers Tower together, with both of them at computers... except Bruce is fully dressed and Tony is wearing his Iron Man helmet and a dressing gown. Eventually: