Seems to me that useless isn't the right word. The Nazis were very efficient at murdering Jews, but they should not have been doing it at all, and I would not say that is merely 'useless'. That's something far worse than useless.
Seen on Twitter: Any English teacher who uses 'they/them' as a singular pronoun should lose their teaching license. (Think about it ... it may take a moment)
@ColinTheMathmo
Seems to me that useless isn't the right word. The Nazis were very efficient at murdering Jews, but they should not have been doing it at all, and I would not say that is merely 'useless'. That's something far worse than useless.