The efficiency of a government is determined by those who direct it, it's not inherent to the structure.
The Manhatten Project, the New Deal, and the Space Race were remarkably efficient and productive, back in the time that we believed that governments can and should do things, and politicians worked together in good faith.
Then corporate lobbyists bought our politicians and convinced us that governments are evil and inept, and that they shouldn't have to pay taxes because the government will just waste it. So we deregulated everything, and now billionares just waste their record profits on low orbit joyrides instead, while average Americans die preventable deaths because they can't afford healthcare (which the governments of every other developed nation manage to provide their citizens for free).
The Manhatten Project, the New Deal, and the Space Race were remarkably efficient and productive, back in the time that we believed that governments can and should do things, and politicians worked together in good faith.
Then corporate lobbyists bought our politicians and convinced us that governments are evil and inept, and that they shouldn't have to pay taxes because the government will just waste it. So we deregulated everything, and now billionares just waste their record profits on low orbit joyrides instead, while average Americans die preventable deaths because they can't afford healthcare (which the governments of every other developed nation manage to provide their citizens for free).