The world isn’t flat
Companies that are successfully embedding new ways or working into their organizations know that a flat organization is not the answer. More agility is often associated with less hierarchy, but similarly to how some people read the agile manifesto, it doesn’t say “no”, but rather “over” or “less of” something.
Global companies require hierarchy for all the reasons you know. The goal isn’t to eliminate hierarchy, it’s to flatten boundaries and bureaucracy by teaching people throughout the organization (top to bottom) to think differently.
The emphasis needs to be on reconsidering how roles within the hierarchical structure behave in a new world and how they encourage new behaviors amongst the teams they interact with. Hierarchy is a good thing and with the right mindset shift it can dramatically change how an organization operates.
Don’t buy into “flattening the organization” as a core principle of transformation. Rather, consider how to flatten the rules and regulations that are preventing or slowing the change.