I'm not sure that you can say definitively that some roles are better filled by consultants, but I would say that some projects are better handled by consultants.

Personal life
Jesse James Garrett grew up in Florida. Career
Jesse James Garrett is a co-founder of Adaptive Path a user experience strategy and design firm and co-founded the Information Architecture Institute. Garrett thought of the term when he realized the need for a shorthand term to represent the suite of technologies he was proposing to a client.

Jesse James Garrett is a user experience designer.