I suspect these types of articles are written by people who have little or no experience with IT in very large organizations, especially with respect to ERP systems. Absent central coordination, companies will end up with higher costs, and systems that don't play well together.

For my employer, IT is responsible for enforcing the budget constraints on computing imposed by senior maangement. If each unit is allowed to do their own IT, you rapidly lose the ability to understand how much IT costs, and how effective it is.

I also suspect that decentralizing IT would result in a major increase in the incidence of cyber-security events as some groups decide not to comply with security policies.