It's more of a tradeoff than just inefficiency/size. Either you push decision making power up the chain so people have a larger view and can see duplicated effort, but then you take longer for each decision as info moves up and down chains (more like apple, Microsoft), or you give teams more autonomy, each team can move faster, but you duplicate effort (amazon, famously with the 'make your shit available to other teams via an api' strategy to mitigate it a bit).