Quote Originally Posted by dragonseth07 View Post
True, but then there is a best spec per fight, and you're expected to switch to that before the fight.

WoW's system in Warlords was exactly this. There were talents for different situations, and it was expected that you change spec on a per-fight basis. At that point, your character no longer had a build. Your build was every talent based on what you fought.
That was largely because the system was almost entirely unrestricted, hence their (false) promise to make talent choices worth more than just a near-free consumable in Legion.

Note that Wrath and Cata didn't run into those issues, primarily because niche was set primarily by spec rather than talent choices (which mostly determined only gameplay and utilities back then), and secondly because you needed to visit a class trainer to swap talents.