It feels like the two qualities overlap in some ways but are different in others. In 2 there was so much detail that you could shoot the blades on a fan and it would spin. A lot of this detail seems to have been lost in the later titles. As someone else put it Far Cry 5 "looks realistic" while Far Cry 2 "is realistic." Maybe they felt that excessive realism didn't contribute to making the game fun, although the impression I got was people saw FC2 as "superior" in some sense because of the attention to detail (such as nearly all vegetation being destructable in 2 but not in 5).