Why Hire a Contractor?

I have seen it done where the other stuff the team needs to do is just so important and they need some extra bandwidth really quick. That often it's on this kind of self-contained chunk of functionality that you're okay handing off to someone else and not having the team own it. I can't imagine a way that this goes successful where if you bring in someone from the outside. To like the reward application. Which the team owns and works on. Meanwhile, like the team is working on something else, I guess.