I have done hard mode plenty of times what are you talking about? I have hard mode hear on my warlock. And yes efficiency is completing a task at the least amount of time possible. They artificially increase the time of the raid and add no difficulty no matter the ability of the player it will just take longer because you can carry less potential damage

All the fights change when u hit that last stage. Once again, GIT GUD.

Uhh no? War priest hard has extra mechanics every time e eats a totem. And oryx added more light eater Knights in the the first phase of the fight.