The film is not a work of genius. If you took away the leads, it'd be pretty boring. I loved every minute of it, and so did Em. I am not sure they could pull off another film with this gimmick, but I definitely think I will enjoy watching what each of these two do in the future of action comedy.
That there are several real male and female characters in The Big Sick is a tribute to its writers, the real life couple whose story is presented in the film. There are very few caricatures in the film. The ones that might qualify are so deftly handled, it just feels like a person we know and not a punchline waiting around to be had.
Let's be serious though. This isn't mensa material. It's a big dumb action comedy. There is nothing here as funny as Thurber's Terry Tate, Office Linebacker and thank goodness there is nothing nearly as bad as We're The Millers. It might get a few sequels, and that's fine. I'm pretty sure I won't remember one joke in 5 years, but I will smile when I think about it, just the same.