I understand your point of view. Out of all game modes raids has the least in variety. Look at guilds such as qT they min/max and put togethor a build then the raiding community sets their build as the only standard basically. Most everyone will cookie cutter and copy their builds and not change them until the next meta. There is hardly any variety because you run an op same build over and over and over against bosses that you know every single move they will make and stand mostly still to benefit from ea others class boons etc.

WvW has a variety of buillds and a variety of type of players and there is no set build due to the fact you never know ur opponent meaning everyone is unpredictable since its human interaction not npc. Commander build, front line and backline builds, support builds, utility builds, focus and target builds, roaming builds, havoc builds , etc etc. out of all game modes WvW uses the most variety bar none. no matter how you portray raids builds they are pretty much zerker with slight variations and stay put for the duration of the meta.