You only have to do it once. If you're coming to a game that's already multiple expansions in you have to expect some grind. Yeah ARR and Pre-HW quest lines are grueling, but once that's over you'll notice it's a lot more trim.

Besides it's a great source of XP to boost up your first character so you get the armory buff for every other class. I got frustrated too but if you bunker down it can go by very quickly. If you wish watch the cutscenes on youtube and skip them in the game.