When we talk about efficiencies it often becomes difficult to figure out who benefits from the efficiency. Airlines may be as efficient as they can be (spend the least amount on wages and fuel per passenger moved) but that does not mean that airline travel is efficient for the passengers. They may stand in long lines, be shunted through airports they do not want to visit and fly at times they do not want to fly. In other words, from the passenger’s point of view, each airline flight is often very inefficient.
Efficiency needs to be evaluated at a system level and the point of view needs to be defined. In 2009 David JC MacKay (1967-2016) wrote a wonderful book called “Sustainable Energy - without the Hot Air” and in that book he very carefully describes present day energy efficiencies and provides guidance on what efficiencies can be achieved. The book received very high praise and he was appointed Chief Scientific Advisor to the UK Department of Energy and Climate Change. However, he made a very interesting error in his analysis.
It is always important to ask “why” about every detail in every design, since bad design imposes a penalty on every user for the life of the bad design.
Bad design can hang around forever even if good design exists. I often ask “why?” when I am forced to use a badly designed cleat on a boat when we have a near perfect design in the 100 year old Herreshoff cleat.
We don't come across enough of these "why's", but I came across a nice one a few days ago.