SOME Addons made the game to easy for skilled players whcih in turn led to the game becoming harder and harder, leaving lesser skilled players behind. Because not even addons can make up for that but make the game trivial for more skilled players. (DBM etc.) Look at the difference between Mythic Nathria compared to naxx in vanilla.... these are WORLDS of difference in difficulty and yes i actually played both. You can even take heroic Nathria. Even that is harder than anything in Classic and tbc. Except maybe SWP with the wrong comp but i am not sure about it until we see it again.
I do not think that Details/recount have a adverse effect on the game. Actually the opposite. People who think the are a gift from god can see where they actually stand and try to be better.