People generally colloquially use efficiency as effectiveness Not if they are talking about specific technical definitions. You should ask these hypothetical p

People generally colloquially use efficiency as effectiveness Not if they are talking about specific technical definitions. You should ask these hypothetical people if they know anything about batteries. However in real systems, that power peoples lives & livelihoods, effective systems are both efficient and available. I don't know what point this vague abstract description is supposed to make, but battery systems are literally working right now and making people money.