I like the fact that it's a baking mix already made up and saves me a smidgeon of time and effort.
Bisquick is the only thing to use for certain recipes. Dumplings, for example. And Impossible Cheeseburger Pie. Oh, and sausage balls. You cannot make sausage balls without Bisquick. I don't care what anyone says, Bisquick pancakes are much better than what people throw together from scratch.