I disagree with the toplevel statement. In high-school science terms, productivity is like accuracy whereas efficiency is like precision. You can be very "productive" at a high-level without being efficient. Similarly you can be quite efficient at your tasks while not managing to achieve the toplevel goal.

You may argue that "analyzing your tasks holistically" will make you more efficient at achieving your goals. But min-maxing is for tactics, and is antithetical to strategy. Very often, taking a nap or a bath or walk will yield an insight that changes the entire game, obviating weeks or months of efficient and diligent work. We've all experienced this, so why do we insist on "maximizing efficiency"?