An external provider's job is to milk you, IT's job is to make things work
An external provider can do the same thing IT does, while charging you more than if you paid the staff yourself, so they make a profit while paying the same staff you would have otherwise paid, as well as paying their marketers. Now instead of rising and falling with you, the people who own your data are interested in their own profit, not yours. Staff at external service providers is rewarded for costing you money, not saving you money like your IT staff is. An IT department that starts acting like an external service provider, not members of an organization is bound to fail. Everyone needs people to fix broken things and make things work, which is what IT should be doing.