Personally I don't see how any fight can be epic without a holy trinity.
The only "mechanics" that can exist without a holy trinity in PVE content boil down to "dodge this", unlike other MMOs where PVE content is so much more complex.
I don't even understand how people can call GW2s combat "dynamic" or "action orientated", it's the same as WoW except you can do something to dodge. WoW has a system where, on some fights, if you click an extra action button you do stuff. This is used in a myriad of heroic encounters and is integral in defeating those encounters.